LinuxLists.cc - [PATCH net-next-2.6 v3] can: Topcliff: PCH

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Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On 11/16/2010 09:39 AM, Tomoya MORINAGA wrote:
> Hi Marc and Wolf,
>
> I have updated your indications.
>
>> * Add Flow control
>> * Fix Data copy issue (endianness)
>> * Add Macro prefix "PCH_"
>> * Separate interface register structure
>> * Some functions are unified.
>> * Change MessageObject indication(PCH_RX_OBJ_START, etc..)
>> * Enumerate LEC macro
>> * Move MSI processing from open/close to probe/remove processing
>> * Use BIT(x)
>> * and more...
>
> Signed-off-by: Tomoya MORINAGA <[email protected]>
> ---
> drivers/net/can/pch_can.c | 1341 ++++++++++++++++++++-------------------------
> 1 files changed, 586 insertions(+), 755 deletions(-)
>
> diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
> index 6727182..bb0f873 100644
> --- a/drivers/net/can/pch_can.c
> +++ b/drivers/net/can/pch_can.c
> @@ -1,6 +1,6 @@
> /*
> * Copyright (C) 1999 - 2010 Intel Corporation.
> - * Copyright (C) 2010 OKI SEMICONDUCTOR Co., LTD.
> + * Copyright (C) 2010 OKI SEMICONDUCTOR CO., LTD.
> *
> * This program is free software; you can redistribute it and/or modify
> * it under the terms of the GNU General Public License as published by
> @@ -32,106 +32,111 @@
> #include <linux/can/dev.h>
> #include <linux/can/error.h>
>
> -#define MAX_MSG_OBJ 32
> -#define MSG_OBJ_RX 0 /* The receive message object flag. */
> -#define MSG_OBJ_TX 1 /* The transmit message object flag. */
> -
> -#define ENABLE 1 /* The enable flag */
> -#define DISABLE 0 /* The disable flag */
> -#define CAN_CTRL_INIT 0x0001 /* The INIT bit of CANCONT register. */
> -#define CAN_CTRL_IE 0x0002 /* The IE bit of CAN control register */
> -#define CAN_CTRL_IE_SIE_EIE 0x000e
> -#define CAN_CTRL_CCE 0x0040
> -#define CAN_CTRL_OPT 0x0080 /* The OPT bit of CANCONT register. */
> -#define CAN_OPT_SILENT 0x0008 /* The Silent bit of CANOPT reg. */
> -#define CAN_OPT_LBACK 0x0010 /* The LoopBack bit of CANOPT reg. */
> -#define CAN_CMASK_RX_TX_SET 0x00f3
> -#define CAN_CMASK_RX_TX_GET 0x0073
> -#define CAN_CMASK_ALL 0xff
> -#define CAN_CMASK_RDWR 0x80
> -#define CAN_CMASK_ARB 0x20
> -#define CAN_CMASK_CTRL 0x10
> -#define CAN_CMASK_MASK 0x40
> -#define CAN_CMASK_NEWDAT 0x04
> -#define CAN_CMASK_CLRINTPND 0x08
> -
> -#define CAN_IF_MCONT_NEWDAT 0x8000
> -#define CAN_IF_MCONT_INTPND 0x2000
> -#define CAN_IF_MCONT_UMASK 0x1000
> -#define CAN_IF_MCONT_TXIE 0x0800
> -#define CAN_IF_MCONT_RXIE 0x0400
> -#define CAN_IF_MCONT_RMTEN 0x0200
> -#define CAN_IF_MCONT_TXRQXT 0x0100
> -#define CAN_IF_MCONT_EOB 0x0080
> -#define CAN_IF_MCONT_DLC 0x000f
> -#define CAN_IF_MCONT_MSGLOST 0x4000
> -#define CAN_MASK2_MDIR_MXTD 0xc000
> -#define CAN_ID2_DIR 0x2000
> -#define CAN_ID_MSGVAL 0x8000
> -
> -#define CAN_STATUS_INT 0x8000
> -#define CAN_IF_CREQ_BUSY 0x8000
> -#define CAN_ID2_XTD 0x4000
> -
> -#define CAN_REC 0x00007f00
> -#define CAN_TEC 0x000000ff
> -
> -#define PCH_RX_OK 0x00000010
> -#define PCH_TX_OK 0x00000008
> -#define PCH_BUS_OFF 0x00000080
> -#define PCH_EWARN 0x00000040
> -#define PCH_EPASSIV 0x00000020
> -#define PCH_LEC0 0x00000001
> -#define PCH_LEC1 0x00000002
> -#define PCH_LEC2 0x00000004
> -#define PCH_LEC_ALL (PCH_LEC0 | PCH_LEC1 | PCH_LEC2)
> -#define PCH_STUF_ERR PCH_LEC0
> -#define PCH_FORM_ERR PCH_LEC1
> -#define PCH_ACK_ERR (PCH_LEC0 | PCH_LEC1)
> -#define PCH_BIT1_ERR PCH_LEC2
> -#define PCH_BIT0_ERR (PCH_LEC0 | PCH_LEC2)
> -#define PCH_CRC_ERR (PCH_LEC1 | PCH_LEC2)
> +#define PCH_CTRL_INIT BIT(0) /* The INIT bit of CANCONT register. */
> +#define PCH_CTRL_IE BIT(1) /* The IE bit of CAN control register */
> +#define PCH_CTRL_IE_SIE_EIE (BIT(3) | BIT(2) | BIT(1))
> +#define PCH_CTRL_CCE BIT(6)
> +#define PCH_CTRL_OPT BIT(7) /* The OPT bit of CANCONT register. */
> +#define PCH_OPT_SILENT BIT(3) /* The Silent bit of CANOPT reg. */
> +#define PCH_OPT_LBACK BIT(4) /* The LoopBack bit of CANOPT reg. */
> +
> +#define PCH_CMASK_RX_TX_SET 0x00f3
> +#define PCH_CMASK_RX_TX_GET 0x0073
> +#define PCH_CMASK_ALL 0xff
> +#define PCH_CMASK_NEWDAT BIT(2)
> +#define PCH_CMASK_CLRINTPND BIT(3)
> +#define PCH_CMASK_CTRL BIT(4)
> +#define PCH_CMASK_ARB BIT(5)
> +#define PCH_CMASK_MASK BIT(6)
> +#define PCH_CMASK_RDWR BIT(7)
> +#define PCH_IF_MCONT_NEWDAT BIT(15)
> +#define PCH_IF_MCONT_MSGLOST BIT(14)
> +#define PCH_IF_MCONT_INTPND BIT(13)
> +#define PCH_IF_MCONT_UMASK BIT(12)
> +#define PCH_IF_MCONT_TXIE BIT(11)
> +#define PCH_IF_MCONT_RXIE BIT(10)
> +#define PCH_IF_MCONT_RMTEN BIT(9)
> +#define PCH_IF_MCONT_TXRQXT BIT(8)
> +#define PCH_IF_MCONT_EOB BIT(7)
> +#define PCH_IF_MCONT_DLC (BIT(0) | BIT(1) | BIT(2) | BIT(3))
> +#define PCH_MASK2_MDIR_MXTD (BIT(14) | BIT(15))
> +#define PCH_ID2_DIR BIT(13)
> +#define PCH_ID2_XTD BIT(14)
> +#define PCH_ID_MSGVAL BIT(15)
> +#define PCH_IF_CREQ_BUSY BIT(15)
> +
> +#define PCH_STATUS_INT 0x8000
> +#define PCH_REC 0x00007f00
> +#define PCH_TEC 0x000000ff
> +
> +#define PCH_TX_OK BIT(3)
> +#define PCH_RX_OK BIT(4)
> +#define PCH_EPASSIV BIT(5)
> +#define PCH_EWARN BIT(6)
> +#define PCH_BUS_OFF BIT(7)
>
> /* bit position of certain controller bits. */
> -#define BIT_BITT_BRP 0
> -#define BIT_BITT_SJW 6
> -#define BIT_BITT_TSEG1 8
> -#define BIT_BITT_TSEG2 12
> -#define BIT_IF1_MCONT_RXIE 10
> -#define BIT_IF2_MCONT_TXIE 11
> -#define BIT_BRPE_BRPE 6
> -#define BIT_ES_TXERRCNT 0
> -#define BIT_ES_RXERRCNT 8
> -#define MSK_BITT_BRP 0x3f
> -#define MSK_BITT_SJW 0xc0
> -#define MSK_BITT_TSEG1 0xf00
> -#define MSK_BITT_TSEG2 0x7000
> -#define MSK_BRPE_BRPE 0x3c0
> -#define MSK_BRPE_GET 0x0f
> -#define MSK_CTRL_IE_SIE_EIE 0x07
> -#define MSK_MCONT_TXIE 0x08
> -#define MSK_MCONT_RXIE 0x10
> -#define PCH_CAN_NO_TX_BUFF 1
> -#define COUNTER_LIMIT 10
> -
> -#define PCH_CAN_CLK 50000000 /* 50MHz */
> -
> -/* Define the number of message object.
> +#define PCH_BIT_BRP_SHIFT 0
> +#define PCH_BIT_SJW_SHIFT 6
> +#define PCH_BIT_TSEG1_SHIFT 8
> +#define PCH_BIT_TSEG2_SHIFT 12
> +#define PCH_BIT_IF1_MCONT_RXIE_SHIFT 10
> +#define PCH_BIT_IF2_MCONT_TXIE_SHIFT 11
> +#define PCH_BIT_BRPE_BRPE_SHIFT 6
> +
> +#define PCH_MSK_BITT_BRP 0x3f
> +#define PCH_MSK_BRPE_BRPE 0x3c0
> +#define PCH_MSK_CTRL_IE_SIE_EIE 0x07
> +#define PCH_COUNTER_LIMIT 10
> +
> +#define PCH_RX_IFREG 0
> +#define PCH_TX_IFREG 1

Please make this an enum. Use this enum in the function arguments
instead of an "u32".

> +
> +#define PCH_CAN_CLK 50000000 /* 50MHz */
> +
> +/*
> + * Define the number of message object.
> * PCH CAN communications are done via Message RAM.
> - * The Message RAM consists of 32 message objects. */
> -#define PCH_RX_OBJ_NUM 26 /* 1~ PCH_RX_OBJ_NUM is Rx*/
> -#define PCH_TX_OBJ_NUM 6 /* PCH_RX_OBJ_NUM is RX ~ Tx*/
> -#define PCH_OBJ_NUM (PCH_TX_OBJ_NUM + PCH_RX_OBJ_NUM)
> + * The Message RAM consists of 32 message objects.
> + */
> +#define PCH_RX_OBJ_NUM 26
> +#define PCH_TX_OBJ_NUM 6
> +#define PCH_RX_OBJ_START 1
> +#define PCH_RX_OBJ_END PCH_RX_OBJ_NUM
> +#define PCH_TX_OBJ_START (PCH_RX_OBJ_END + 1)
> +#define PCH_TX_OBJ_END (PCH_RX_OBJ_NUM + PCH_TX_OBJ_NUM)
>
> #define PCH_FIFO_THRESH 16
>
> +enum pch_can_err {
> + PCH_STUF_ERR = 1,
> + PCH_FORM_ERR,
> + PCH_ACK_ERR,
> + PCH_BIT1_ERR,
> + PCH_BIT0_ERR,
> + PCH_CRC_ERR,
> + PCH_LEC_ALL,
> +};
> +
> enum pch_can_mode {
> PCH_CAN_ENABLE,
> PCH_CAN_DISABLE,
> PCH_CAN_ALL,
> PCH_CAN_NONE,
> PCH_CAN_STOP,
> - PCH_CAN_RUN
> + PCH_CAN_RUN,
> +};
> +
> +struct pch_can_if_regs {
> + u32 creq;
> + u32 cmask;
> + u32 mask1;
> + u32 mask2;
> + u32 id1;
> + u32 id2;
> + u32 mcont;
> + u32 data[4];
> + u32 rsv[13];
> };
>
> struct pch_can_regs {
> @@ -142,53 +147,34 @@ struct pch_can_regs {
> u32 intr;
> u32 opt;
> u32 brpe;
> - u32 reserve1;
> - u32 if1_creq;
> - u32 if1_cmask;
> - u32 if1_mask1;
> - u32 if1_mask2;
> - u32 if1_id1;
> - u32 if1_id2;
> - u32 if1_mcont;
> - u32 if1_dataa1;
> - u32 if1_dataa2;
> - u32 if1_datab1;
> - u32 if1_datab2;
> - u32 reserve2;
> - u32 reserve3[12];
> - u32 if2_creq;
> - u32 if2_cmask;
> - u32 if2_mask1;
> - u32 if2_mask2;
> - u32 if2_id1;
> - u32 if2_id2;
> - u32 if2_mcont;
> - u32 if2_dataa1;
> - u32 if2_dataa2;
> - u32 if2_datab1;
> - u32 if2_datab2;
> - u32 reserve4;
> - u32 reserve5[20];
> + u32 reserve;
> + struct pch_can_if_regs ifregs[2]; /* [0]=if1 [1]=if2 */
> + u32 reserve1[8];
> u32 treq1;
> u32 treq2;
> - u32 reserve6[2];
> - u32 reserve7[56];
> - u32 reserve8[3];
> + u32 reserve2[6];
> + u32 data1;
> + u32 data2;
> + u32 reserve3[6];
> + u32 canipend1;
> + u32 canipend2;
> + u32 reserve4[6];
> + u32 canmval1;
> + u32 canmval2;
> + u32 reserve5[37];
> u32 srst;
> };
>
> struct pch_can_priv {
> struct can_priv can;
> - unsigned int can_num;
> struct pci_dev *dev;
> - unsigned int tx_enable[MAX_MSG_OBJ];
> - unsigned int rx_enable[MAX_MSG_OBJ];
> - unsigned int rx_link[MAX_MSG_OBJ];
> + unsigned int tx_enable[PCH_TX_OBJ_END];
> + unsigned int rx_enable[PCH_TX_OBJ_END];
> + unsigned int rx_link[PCH_TX_OBJ_END];
> unsigned int int_enables;
> unsigned int int_stat;
> struct net_device *ndev;
> - spinlock_t msgif_reg_lock; /* Message Interface Registers Access Lock*/
> - unsigned int msg_obj[MAX_MSG_OBJ];
> + unsigned int msg_obj[PCH_TX_OBJ_END];
> struct pch_can_regs __iomem *regs;
> struct napi_struct napi;
> unsigned int tx_obj; /* Point next Tx Obj index */
> @@ -228,15 +214,15 @@ static void pch_can_set_run_mode(struct pch_can_priv *priv,
> {
> switch (mode) {
> case PCH_CAN_RUN:
> - pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_INIT);
> + pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_INIT);
> break;
>
> case PCH_CAN_STOP:
> - pch_can_bit_set(&priv->regs->cont, CAN_CTRL_INIT);
> + pch_can_bit_set(&priv->regs->cont, PCH_CTRL_INIT);
> break;
>
> default:
> - dev_err(&priv->ndev->dev, "%s -> Invalid Mode.\n", __func__);
> + netdev_err(priv->ndev, "%s -> Invalid Mode.\n", __func__);
> break;
> }
> }
> @@ -246,357 +232,184 @@ static void pch_can_set_optmode(struct pch_can_priv *priv)
> u32 reg_val = ioread32(&priv->regs->opt);
>
> if (priv->can.ctrlmode & CAN_CTRLMODE_LISTENONLY)
> - reg_val |= CAN_OPT_SILENT;
> + reg_val |= PCH_OPT_SILENT;
>
> if (priv->can.ctrlmode & CAN_CTRLMODE_LOOPBACK)
> - reg_val |= CAN_OPT_LBACK;
> + reg_val |= PCH_OPT_LBACK;
>
> - pch_can_bit_set(&priv->regs->cont, CAN_CTRL_OPT);
> + pch_can_bit_set(&priv->regs->cont, PCH_CTRL_OPT);
> iowrite32(reg_val, &priv->regs->opt);
> }
>
> -static void pch_can_set_int_custom(struct pch_can_priv *priv)
> +static void pch_can_rw_msg_obj(void __iomem *creq_addr, u32 num)
> {
> - /* Clearing the IE, SIE and EIE bits of Can control register. */
> - pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
> -
> - /* Appropriately setting them. */
> - pch_can_bit_set(&priv->regs->cont,
> - ((priv->int_enables & MSK_CTRL_IE_SIE_EIE) << 1));
> -}
> + int counter = PCH_COUNTER_LIMIT;
> + u32 ifx_creq;
>
> -/* This function retrieves interrupt enabled for the CAN device. */
> -static void pch_can_get_int_enables(struct pch_can_priv *priv, u32 *enables)
> -{
> - /* Obtaining the status of IE, SIE and EIE interrupt bits. */
> - *enables = ((ioread32(&priv->regs->cont) & CAN_CTRL_IE_SIE_EIE) >> 1);
> + iowrite32(num, creq_addr);
> + while (counter) {
> + ifx_creq = ioread32(creq_addr) & PCH_IF_CREQ_BUSY;
> + if (!ifx_creq)
> + break;
> + counter--;
> + udelay(1);
> + }
> + if (!counter)
> + pr_err("%s:IF1 BUSY Flag is set forever.\n", __func__);
> }
>
> static void pch_can_set_int_enables(struct pch_can_priv *priv,
> enum pch_can_mode interrupt_no)
> {
> switch (interrupt_no) {
> - case PCH_CAN_ENABLE:
> - pch_can_bit_set(&priv->regs->cont, CAN_CTRL_IE);
> - break;
> -
> case PCH_CAN_DISABLE:
> - pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE);
> + pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE);
> break;
>
> case PCH_CAN_ALL:
> - pch_can_bit_set(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
> + pch_can_bit_set(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
> break;
>
> case PCH_CAN_NONE:
> - pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_IE_SIE_EIE);
> + pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
> break;
>
> default:
> - dev_err(&priv->ndev->dev, "Invalid interrupt number.\n");
> + netdev_err(priv->ndev, "Invalid interrupt number.\n");
> break;
> }
> }
>
> -static void pch_can_check_if_busy(u32 __iomem *creq_addr, u32 num)
> +static void pch_can_set_rxtx(struct pch_can_priv *priv, u32 buff_num,
> + u32 set, u32 dir)
^^^^^^^

Please make "set" a normal int (or bool).

> {
> - u32 counter = COUNTER_LIMIT;
> - u32 ifx_creq;
> + u32 ie;
>
> - iowrite32(num, creq_addr);
> - while (counter) {
> - ifx_creq = ioread32(creq_addr) & CAN_IF_CREQ_BUSY;
> - if (!ifx_creq)
> - break;
> - counter--;
> - udelay(1);
> - }
> - if (!counter)
> - pr_err("%s:IF1 BUSY Flag is set forever.\n", __func__);
> -}
> -
> -static void pch_can_set_rx_enable(struct pch_can_priv *priv, u32 buff_num,
> - u32 set)
> -{
> - unsigned long flags;
> -
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> - /* Reading the receive buffer data from RAM to Interface1 registers */
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
> -
> - /* Setting the IF1MASK1 register to access MsgVal and RxIE bits */
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_ARB | CAN_CMASK_CTRL,
> - &priv->regs->if1_cmask);
> -
> - if (set == ENABLE) {
> - /* Setting the MsgVal and RxIE bits */
> - pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_RXIE);
> - pch_can_bit_set(&priv->regs->if1_id2, CAN_ID_MSGVAL);
> -
> - } else if (set == DISABLE) {
> - /* Resetting the MsgVal and RxIE bits */
> - pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_RXIE);
> - pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID_MSGVAL);
> - }
> -
> - pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> -}
> -
> -static void pch_can_rx_enable_all(struct pch_can_priv *priv)
> -{
> - int i;
> -
> - /* Traversing to obtain the object configured as receivers. */
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_RX)
> - pch_can_set_rx_enable(priv, i + 1, ENABLE);
> - }
> -}
> -
> -static void pch_can_rx_disable_all(struct pch_can_priv *priv)
> -{
> - int i;
> -
> - /* Traversing to obtain the object configured as receivers. */
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_RX)
> - pch_can_set_rx_enable(priv, i + 1, DISABLE);
> - }
> -}
> -
> -static void pch_can_set_tx_enable(struct pch_can_priv *priv, u32 buff_num,
> - u32 set)
> -{
> - unsigned long flags;
> + if (dir)
> + ie = PCH_IF_MCONT_TXIE;
> + else
> + ie = PCH_IF_MCONT_RXIE;
>
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> /* Reading the Msg buffer from Message RAM to Interface2 registers. */
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
> - pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
> + iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
>
> /* Setting the IF2CMASK register for accessing the
> MsgVal and TxIE bits */

can you fix this multiline comment, please

> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_ARB | CAN_CMASK_CTRL,
> - &priv->regs->if2_cmask);
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_ARB | PCH_CMASK_CTRL,
> + &priv->regs->ifregs[dir].cmask);
>
> - if (set == ENABLE) {
> + if (set) {
> /* Setting the MsgVal and TxIE bits */
> - pch_can_bit_set(&priv->regs->if2_mcont, CAN_IF_MCONT_TXIE);
> - pch_can_bit_set(&priv->regs->if2_id2, CAN_ID_MSGVAL);
> - } else if (set == DISABLE) {
> + pch_can_bit_set(&priv->regs->ifregs[dir].mcont, ie);
> + pch_can_bit_set(&priv->regs->ifregs[dir].id2, PCH_ID_MSGVAL);
> + } else {
> /* Resetting the MsgVal and TxIE bits. */
> - pch_can_bit_clear(&priv->regs->if2_mcont, CAN_IF_MCONT_TXIE);
> - pch_can_bit_clear(&priv->regs->if2_id2, CAN_ID_MSGVAL);
> + pch_can_bit_clear(&priv->regs->ifregs[dir].mcont, ie);
> + pch_can_bit_clear(&priv->regs->ifregs[dir].id2, PCH_ID_MSGVAL);
> }
>
> - pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
> }
>
> -static void pch_can_tx_enable_all(struct pch_can_priv *priv)
> +static void pch_can_set_rx_all(struct pch_can_priv *priv, u32 set)
> {
> int i;
>
> - /* Traversing to obtain the object configured as transmit object. */
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_TX)
> - pch_can_set_tx_enable(priv, i + 1, ENABLE);
> - }
> + /* Traversing to obtain the object configured as receivers. */
> + for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++)
> + pch_can_set_rxtx(priv, i, set, PCH_RX_IFREG);
> }
>
> -static void pch_can_tx_disable_all(struct pch_can_priv *priv)
> +static void pch_can_set_tx_all(struct pch_can_priv *priv, u32 set)
> {
> int i;
>
> - /* Traversing to obtain the object configured as transmit object. */
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_TX)
> - pch_can_set_tx_enable(priv, i + 1, DISABLE);
> - }
> -}
> -
> -static void pch_can_get_rx_enable(struct pch_can_priv *priv, u32 buff_num,
> - u32 *enable)
> -{
> - unsigned long flags;
> -
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, buff_num);
> -
> - if (((ioread32(&priv->regs->if1_id2)) & CAN_ID_MSGVAL) &&
> - ((ioread32(&priv->regs->if1_mcont)) &
> - CAN_IF_MCONT_RXIE))
> - *enable = ENABLE;
> - else
> - *enable = DISABLE;
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> -}
> -
> -static void pch_can_get_tx_enable(struct pch_can_priv *priv, u32 buff_num,
> - u32 *enable)
> -{
> - unsigned long flags;
> -
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
> - pch_can_check_if_busy(&priv->regs->if2_creq, buff_num);
> -
> - if (((ioread32(&priv->regs->if2_id2)) & CAN_ID_MSGVAL) &&
> - ((ioread32(&priv->regs->if2_mcont)) &
> - CAN_IF_MCONT_TXIE)) {
> - *enable = ENABLE;
> - } else {
> - *enable = DISABLE;
> - }
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> + /* Traversing to obtain the object configured as receivers. */
> + for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++)
> + pch_can_set_rxtx(priv, i, set, PCH_TX_IFREG);
> }
>
> -static int pch_can_int_pending(struct pch_can_priv *priv)
> +static u32 pch_can_int_pending(struct pch_can_priv *priv)
> {
> return ioread32(&priv->regs->intr) & 0xffff;
> }
>
> -static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
> - u32 buffer_num, u32 set)
> -{
> - unsigned long flags;
> -
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL, &priv->regs->if1_cmask);
> - if (set == ENABLE)
> - pch_can_bit_clear(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
> - else
> - pch_can_bit_set(&priv->regs->if1_mcont, CAN_IF_MCONT_EOB);
> -
> - pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> -}
> -
> -static void pch_can_get_rx_buffer_link(struct pch_can_priv *priv,
> - u32 buffer_num, u32 *link)
> +static void pch_can_clear_if_buffers(struct pch_can_priv *priv)
> {
> - unsigned long flags;
> -
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, buffer_num);
> -
> - if (ioread32(&priv->regs->if1_mcont) & CAN_IF_MCONT_EOB)
> - *link = DISABLE;
> - else
> - *link = ENABLE;
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> -}
> -
> -static void pch_can_clear_buffers(struct pch_can_priv *priv)
> -{
> - int i;
> -
> - for (i = 0; i < PCH_RX_OBJ_NUM; i++) {
> - iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if1_cmask);
> - iowrite32(0xffff, &priv->regs->if1_mask1);
> - iowrite32(0xffff, &priv->regs->if1_mask2);
> - iowrite32(0x0, &priv->regs->if1_id1);
> - iowrite32(0x0, &priv->regs->if1_id2);
> - iowrite32(0x0, &priv->regs->if1_mcont);
> - iowrite32(0x0, &priv->regs->if1_dataa1);
> - iowrite32(0x0, &priv->regs->if1_dataa2);
> - iowrite32(0x0, &priv->regs->if1_datab1);
> - iowrite32(0x0, &priv->regs->if1_datab2);
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
> - CAN_CMASK_ARB | CAN_CMASK_CTRL,
> - &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, i+1);
> - }
> -
> - for (i = i; i < PCH_OBJ_NUM; i++) {
> - iowrite32(CAN_CMASK_RX_TX_SET, &priv->regs->if2_cmask);
> - iowrite32(0xffff, &priv->regs->if2_mask1);
> - iowrite32(0xffff, &priv->regs->if2_mask2);
> - iowrite32(0x0, &priv->regs->if2_id1);
> - iowrite32(0x0, &priv->regs->if2_id2);
> - iowrite32(0x0, &priv->regs->if2_mcont);
> - iowrite32(0x0, &priv->regs->if2_dataa1);
> - iowrite32(0x0, &priv->regs->if2_dataa2);
> - iowrite32(0x0, &priv->regs->if2_datab1);
> - iowrite32(0x0, &priv->regs->if2_datab2);
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
> - CAN_CMASK_ARB | CAN_CMASK_CTRL,
> - &priv->regs->if2_cmask);
> - pch_can_check_if_busy(&priv->regs->if2_creq, i+1);
> + int i; /* Msg Obj ID (1~32) */
> +
> + for (i = PCH_RX_OBJ_START; i <= PCH_TX_OBJ_END; i++) {
> + iowrite32(PCH_CMASK_RX_TX_SET, &priv->regs->ifregs[0].cmask);
> + iowrite32(0xffff, &priv->regs->ifregs[0].mask1);
> + iowrite32(0xffff, &priv->regs->ifregs[0].mask2);
> + iowrite32(0x0, &priv->regs->ifregs[0].id1);
> + iowrite32(0x0, &priv->regs->ifregs[0].id2);
> + iowrite32(0x0, &priv->regs->ifregs[0].mcont);
> + iowrite32(0x0, &priv->regs->ifregs[0].data[0]);
> + iowrite32(0x0, &priv->regs->ifregs[0].data[1]);
> + iowrite32(0x0, &priv->regs->ifregs[0].data[2]);
> + iowrite32(0x0, &priv->regs->ifregs[0].data[3]);
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK |
> + PCH_CMASK_ARB | PCH_CMASK_CTRL,
> + &priv->regs->ifregs[0].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
> }
> }
>
> static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)
> {
> int i;
> - unsigned long flags;
> -
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_RX) {
> - iowrite32(CAN_CMASK_RX_TX_GET,
> - &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, i+1);
> + for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
> + iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
>
> - iowrite32(0x0, &priv->regs->if1_id1);
> - iowrite32(0x0, &priv->regs->if1_id2);
> + iowrite32(0x0, &priv->regs->ifregs[0].id1);
> + iowrite32(0x0, &priv->regs->ifregs[0].id2);
>
> - pch_can_bit_set(&priv->regs->if1_mcont,
> - CAN_IF_MCONT_UMASK);
> + pch_can_bit_set(&priv->regs->ifregs[0].mcont,
> + PCH_IF_MCONT_UMASK);
>
> - /* Set FIFO mode set to 0 except last Rx Obj*/
> - pch_can_bit_clear(&priv->regs->if1_mcont,
> - CAN_IF_MCONT_EOB);
> - /* In case FIFO mode, Last EoB of Rx Obj must be 1 */
> - if (i == (PCH_RX_OBJ_NUM - 1))
> - pch_can_bit_set(&priv->regs->if1_mcont,
> - CAN_IF_MCONT_EOB);
> + if (i == PCH_RX_OBJ_END)
> + pch_can_bit_set(&priv->regs->ifregs[0].mcont,
> + PCH_IF_MCONT_EOB);
> + else
> + pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
> + PCH_IF_MCONT_EOB);
>
> - iowrite32(0, &priv->regs->if1_mask1);
> - pch_can_bit_clear(&priv->regs->if1_mask2,
> - 0x1fff | CAN_MASK2_MDIR_MXTD);
> + iowrite32(0, &priv->regs->ifregs[0].mask1);
> + pch_can_bit_clear(&priv->regs->ifregs[0].mask2,
> + 0x1fff | PCH_MASK2_MDIR_MXTD);
>
> - /* Setting CMASK for writing */
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
> - CAN_CMASK_ARB | CAN_CMASK_CTRL,
> - &priv->regs->if1_cmask);
> + /* Setting CMASK for writing */
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK | PCH_CMASK_ARB |
> + PCH_CMASK_CTRL, &priv->regs->ifregs[0].cmask);
>
> - pch_can_check_if_busy(&priv->regs->if1_creq, i+1);
> - } else if (priv->msg_obj[i] == MSG_OBJ_TX) {
> - iowrite32(CAN_CMASK_RX_TX_GET,
> - &priv->regs->if2_cmask);
> - pch_can_check_if_busy(&priv->regs->if2_creq, i+1);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, i);
> + }
>
> - /* Resetting DIR bit for reception */
> - iowrite32(0x0, &priv->regs->if2_id1);
> - iowrite32(0x0, &priv->regs->if2_id2);
> - pch_can_bit_set(&priv->regs->if2_id2, CAN_ID2_DIR);
> + for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++) {
> + iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[1].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, i);
>
> - /* Setting EOB bit for transmitter */
> - iowrite32(CAN_IF_MCONT_EOB, &priv->regs->if2_mcont);
> + /* Resetting DIR bit for reception */
> + iowrite32(0x0, &priv->regs->ifregs[1].id1);
> + iowrite32(PCH_ID2_DIR, &priv->regs->ifregs[1].id2);
>
> - pch_can_bit_set(&priv->regs->if2_mcont,
> - CAN_IF_MCONT_UMASK);
> + /* Setting EOB bit for transmitter */
> + iowrite32(PCH_IF_MCONT_EOB | PCH_IF_MCONT_UMASK,
> + &priv->regs->ifregs[1].mcont);
>
> - iowrite32(0, &priv->regs->if2_mask1);
> - pch_can_bit_clear(&priv->regs->if2_mask2, 0x1fff);
> + iowrite32(0, &priv->regs->ifregs[1].mask1);
> + pch_can_bit_clear(&priv->regs->ifregs[1].mask2, 0x1fff);
>
> - /* Setting CMASK for writing */
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_MASK |
> - CAN_CMASK_ARB | CAN_CMASK_CTRL,
> - &priv->regs->if2_cmask);
> + /* Setting CMASK for writing */
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_MASK | PCH_CMASK_ARB |
> + PCH_CMASK_CTRL, &priv->regs->ifregs[1].cmask);
>
> - pch_can_check_if_busy(&priv->regs->if2_creq, i+1);
> - }
> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, i);
> }
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> }
>
> static void pch_can_init(struct pch_can_priv *priv)
> @@ -605,7 +418,7 @@ static void pch_can_init(struct pch_can_priv *priv)
> pch_can_set_run_mode(priv, PCH_CAN_STOP);
>
> /* Clearing all the message object buffers. */
> - pch_can_clear_buffers(priv);
> + pch_can_clear_if_buffers(priv);
>
> /* Configuring the respective message object as either rx/tx object. */
> pch_can_config_rx_tx_buffers(priv);
> @@ -623,57 +436,53 @@ static void pch_can_release(struct pch_can_priv *priv)
> pch_can_set_int_enables(priv, PCH_CAN_NONE);
>
> /* Disabling all the receive object. */
> - pch_can_rx_disable_all(priv);
> + pch_can_set_rx_all(priv, 0);
>
> /* Disabling all the transmit object. */
> - pch_can_tx_disable_all(priv);
> + pch_can_set_tx_all(priv, 0);
> }
>
> /* This function clears interrupt(s) from the CAN device. */
> static void pch_can_int_clr(struct pch_can_priv *priv, u32 mask)
> {
> - if (mask == CAN_STATUS_INT) {
> - ioread32(&priv->regs->stat);
> - return;
> - }
> -
> /* Clear interrupt for transmit object */
> - if (priv->msg_obj[mask - 1] == MSG_OBJ_TX) {
> - /* Setting CMASK for clearing interrupts for
> - frame transmission. */
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL | CAN_CMASK_ARB,
> - &priv->regs->if2_cmask);
> -
> - /* Resetting the ID registers. */
> - pch_can_bit_set(&priv->regs->if2_id2,
> - CAN_ID2_DIR | (0x7ff << 2));
> - iowrite32(0x0, &priv->regs->if2_id1);
> -
> - /* Claring NewDat, TxRqst & IntPnd */
> - pch_can_bit_clear(&priv->regs->if2_mcont,
> - CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND |
> - CAN_IF_MCONT_TXRQXT);
> - pch_can_check_if_busy(&priv->regs->if2_creq, mask);
> - } else if (priv->msg_obj[mask - 1] == MSG_OBJ_RX) {
> + if ((mask >= PCH_RX_OBJ_START) && (mask <= PCH_RX_OBJ_END)) {
> /* Setting CMASK for clearing the reception interrupts. */
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL | CAN_CMASK_ARB,
> - &priv->regs->if1_cmask);
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL | PCH_CMASK_ARB,
> + &priv->regs->ifregs[0].cmask);
>
> /* Clearing the Dir bit. */
> - pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID2_DIR);
> + pch_can_bit_clear(&priv->regs->ifregs[0].id2, PCH_ID2_DIR);
>
> /* Clearing NewDat & IntPnd */
> - pch_can_bit_clear(&priv->regs->if1_mcont,
> - CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND);
> + pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
> + PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_INTPND);
>
> - pch_can_check_if_busy(&priv->regs->if1_creq, mask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, mask);
> + } else if ((mask >= PCH_TX_OBJ_START) && (mask <= PCH_TX_OBJ_END)) {
> + /*
> + * Setting CMASK for clearing interrupts for frame transmission.
> + */
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL | PCH_CMASK_ARB,
> + &priv->regs->ifregs[1].cmask);
> +
> + /* Resetting the ID registers. */
> + pch_can_bit_set(&priv->regs->ifregs[1].id2,
> + PCH_ID2_DIR | (0x7ff << 2));
> + iowrite32(0x0, &priv->regs->ifregs[1].id1);
> +
> + /* Claring NewDat, TxRqst & IntPnd */
> + pch_can_bit_clear(&priv->regs->ifregs[1].mcont,
> + PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_INTPND |
> + PCH_IF_MCONT_TXRQXT);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, mask);
> }
> }
>
> -static int pch_can_get_buffer_status(struct pch_can_priv *priv)
> +static u32 pch_can_get_buffer_status(struct pch_can_priv *priv)
> {
> return (ioread32(&priv->regs->treq1) & 0xffff) |
> - ((ioread32(&priv->regs->treq2) & 0xffff) << 16);
> + (ioread32(&priv->regs->treq2) << 16);
> }
>
> static void pch_can_reset(struct pch_can_priv *priv)
> @@ -688,7 +497,7 @@ static void pch_can_error(struct net_device *ndev, u32 status)
> struct sk_buff *skb;
> struct pch_can_priv *priv = netdev_priv(ndev);
> struct can_frame *cf;
> - u32 errc;
> + u32 errc, lec;
> struct net_device_stats *stats = &(priv->ndev->stats);
> enum can_state state = priv->can.state;
>
> @@ -697,26 +506,24 @@ static void pch_can_error(struct net_device *ndev, u32 status)
> return;
>
> if (status & PCH_BUS_OFF) {
> - pch_can_tx_disable_all(priv);
> - pch_can_rx_disable_all(priv);
> + pch_can_set_tx_all(priv, 0);
> + pch_can_set_rx_all(priv, 0);
> state = CAN_STATE_BUS_OFF;
> cf->can_id |= CAN_ERR_BUSOFF;
> can_bus_off(ndev);
> - pch_can_set_run_mode(priv, PCH_CAN_RUN);
> - dev_err(&ndev->dev, "%s -> Bus Off occurres.\n", __func__);
> }
>
> + errc = ioread32(&priv->regs->errc);
> /* Warning interrupt. */
> if (status & PCH_EWARN) {
> state = CAN_STATE_ERROR_WARNING;
> priv->can.can_stats.error_warning++;
> cf->can_id |= CAN_ERR_CRTL;
> - errc = ioread32(&priv->regs->errc);
> - if (((errc & CAN_REC) >> 8) > 96)
> + if (((errc & PCH_REC) >> 8) > 96)
> cf->data[1] |= CAN_ERR_CRTL_RX_WARNING;
> - if ((errc & CAN_TEC) > 96)
> + if ((errc & PCH_TEC) > 96)
> cf->data[1] |= CAN_ERR_CRTL_TX_WARNING;
> - dev_warn(&ndev->dev,
> + netdev_dbg(ndev,
> "%s -> Error Counter is more than 96.\n", __func__);
> }
> /* Error passive interrupt. */
> @@ -724,46 +531,52 @@ static void pch_can_error(struct net_device *ndev, u32 status)
> priv->can.can_stats.error_passive++;
> state = CAN_STATE_ERROR_PASSIVE;
> cf->can_id |= CAN_ERR_CRTL;
> - errc = ioread32(&priv->regs->errc);
> - if (((errc & CAN_REC) >> 8) > 127)
> + if (((errc & PCH_REC) >> 8) > 127)
> cf->data[1] |= CAN_ERR_CRTL_RX_PASSIVE;
> - if ((errc & CAN_TEC) > 127)
> + if ((errc & PCH_TEC) > 127)
> cf->data[1] |= CAN_ERR_CRTL_TX_PASSIVE;
> - dev_err(&ndev->dev,
> + netdev_dbg(ndev,
> "%s -> CAN controller is ERROR PASSIVE .\n", __func__);
> }
>
> - if (status & PCH_LEC_ALL) {
> + lec = status & PCH_LEC_ALL;
> + switch (lec) {
> + case PCH_STUF_ERR:
> + cf->data[2] |= CAN_ERR_PROT_STUFF;
> priv->can.can_stats.bus_error++;
> stats->rx_errors++;
> - switch (status & PCH_LEC_ALL) {
> - case PCH_STUF_ERR:
> - cf->data[2] |= CAN_ERR_PROT_STUFF;
> - break;
> - case PCH_FORM_ERR:
> - cf->data[2] |= CAN_ERR_PROT_FORM;
> - break;
> - case PCH_ACK_ERR:
> - cf->data[2] |= CAN_ERR_PROT_LOC_ACK |
> - CAN_ERR_PROT_LOC_ACK_DEL;
> - break;
> - case PCH_BIT1_ERR:
> - case PCH_BIT0_ERR:
> - cf->data[2] |= CAN_ERR_PROT_BIT;
> - break;
> - case PCH_CRC_ERR:
> - cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ |
> - CAN_ERR_PROT_LOC_CRC_DEL;
> - break;
> - default:
> - iowrite32(status | PCH_LEC_ALL, &priv->regs->stat);
> - break;
> - }
> -
> + break;
> + case PCH_FORM_ERR:
> + cf->data[2] |= CAN_ERR_PROT_FORM;
> + priv->can.can_stats.bus_error++;
> + stats->rx_errors++;
> + break;
> + case PCH_ACK_ERR:
> + cf->can_id |= CAN_ERR_ACK;
> + priv->can.can_stats.bus_error++;
> + stats->rx_errors++;
> + break;
> + case PCH_BIT1_ERR:
> + case PCH_BIT0_ERR:
> + cf->data[2] |= CAN_ERR_PROT_BIT;
> + priv->can.can_stats.bus_error++;
> + stats->rx_errors++;
> + break;
> + case PCH_CRC_ERR:
> + cf->data[2] |= CAN_ERR_PROT_LOC_CRC_SEQ |
> + CAN_ERR_PROT_LOC_CRC_DEL;
> + priv->can.can_stats.bus_error++;
> + stats->rx_errors++;
> + break;
> + case PCH_LEC_ALL: /* Written by CPU. No error status */
> + break;
> }
>
> + cf->data[6] = errc & PCH_TEC;
> + cf->data[7] = (errc & PCH_REC) >> 8;
> +
> priv->can.state = state;
> - netif_rx(skb);
> + netif_receive_skb(skb);
>
> stats->rx_packets++;
> stats->rx_bytes += cf->can_dlc;
> @@ -775,199 +588,207 @@ static irqreturn_t pch_can_interrupt(int irq, void *dev_id)
> struct pch_can_priv *priv = netdev_priv(ndev);
>
> pch_can_set_int_enables(priv, PCH_CAN_NONE);
> -
> napi_schedule(&priv->napi);
>
> return IRQ_HANDLED;
> }
>
> -static int pch_can_rx_normal(struct net_device *ndev, u32 int_stat)
> +static void pch_fifo_thresh(struct pch_can_priv *priv, int obj_id)
> +{
> + if (obj_id < PCH_FIFO_THRESH) {
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL |
> + PCH_CMASK_ARB, &priv->regs->ifregs[0].cmask);
> +
> + /* Clearing the Dir bit. */
> + pch_can_bit_clear(&priv->regs->ifregs[0].id2, PCH_ID2_DIR);
> +
> + /* Clearing NewDat & IntPnd */
> + pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
> + PCH_IF_MCONT_INTPND);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_id);
> + } else if (obj_id > PCH_FIFO_THRESH) {
> + pch_can_int_clr(priv, obj_id);
> + } else if (obj_id == PCH_FIFO_THRESH) {
> + int cnt;
> + for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)
> + pch_can_int_clr(priv, cnt+1);
> + }
> +}
> +
> +static int pch_can_rx_msg_lost(struct net_device *ndev, int obj_id)
> +{
> + struct pch_can_priv *priv = netdev_priv(ndev);
> + struct net_device_stats *stats = &(priv->ndev->stats);
> + struct sk_buff *skb;
> + struct can_frame *cf;
> +
> + netdev_dbg(priv->ndev, "Msg Obj is overwritten.\n");
> + pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
> + PCH_IF_MCONT_MSGLOST);
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,
> + &priv->regs->ifregs[0].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_id);
> +
> + skb = alloc_can_err_skb(ndev, &cf);
> + if (!skb)
> + return -ENOMEM;
> +
> + cf->can_id |= CAN_ERR_CRTL;
> + cf->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
> + stats->rx_over_errors++;
> + stats->rx_errors++;
> +
> + netif_receive_skb(skb);
> +
> + return 0;
> +}
> +
> +static int pch_can_rx_normal(struct net_device *ndev, u32 obj_num, int quota)
> {
> u32 reg;
> canid_t id;
> - u32 ide;
> - u32 rtr;
> - int i, j, k;
> int rcv_pkts = 0;
> + int rtn;
> + int next_flag = 0;
> struct sk_buff *skb;
> struct can_frame *cf;
> struct pch_can_priv *priv = netdev_priv(ndev);
> struct net_device_stats *stats = &(priv->ndev->stats);
> + int i;
> + u32 id2;
> + u16 data_reg;
>
> - /* Reading the messsage object from the Message RAM */
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, int_stat);
> + do {
> + /* Reading the messsage object from the Message RAM */
> + iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, obj_num);
>
> - /* Reading the MCONT register. */
> - reg = ioread32(&priv->regs->if1_mcont);
> - reg &= 0xffff;
> + /* Reading the MCONT register. */
> + reg = ioread32(&priv->regs->ifregs[0].mcont);
> +
> + if (reg & PCH_IF_MCONT_EOB)
> + break;
>
> - for (k = int_stat; !(reg & CAN_IF_MCONT_EOB); k++) {
> /* If MsgLost bit set. */
> - if (reg & CAN_IF_MCONT_MSGLOST) {
> - dev_err(&priv->ndev->dev, "Msg Obj is overwritten.\n");
> - pch_can_bit_clear(&priv->regs->if1_mcont,
> - CAN_IF_MCONT_MSGLOST);
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL,
> - &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, k);
> -
> - skb = alloc_can_err_skb(ndev, &cf);
> + if (reg & PCH_IF_MCONT_MSGLOST) {
> + rtn = pch_can_rx_msg_lost(ndev, obj_num);
> + if (!rtn)
> + return rtn;

I would return "rcv_pkgs" even in case of an error (or continue
working), because "pch_can_rx_poll" does a "quota -= rcv_pkts;"

> + rcv_pkts++;
> + quota--;
> + next_flag = 1;
> + } else if (!(reg & PCH_IF_MCONT_NEWDAT))
> + next_flag = 1;
> +
> + if (!next_flag) {

Regarding the "next_flag", it's just the "obj_num++;" that needs to be
reorganized, then you can get rid of the next_flag and use just "continue".

> + skb = alloc_can_skb(priv->ndev, &cf);
> if (!skb)
> return -ENOMEM;
>
> - priv->can.can_stats.error_passive++;
> - priv->can.state = CAN_STATE_ERROR_PASSIVE;
> - cf->can_id |= CAN_ERR_CRTL;
> - cf->data[1] |= CAN_ERR_CRTL_RX_OVERFLOW;
> - cf->data[2] |= CAN_ERR_PROT_OVERLOAD;
> - stats->rx_packets++;
> - stats->rx_bytes += cf->can_dlc;
> + /* Get Received data */
> + id2 = ioread32(&priv->regs->ifregs[0].id2);
> + if (id2 & PCH_ID2_XTD) {
> + id = (ioread32(&priv->regs->ifregs[0].id1) &
> + 0xffff);
> + id |= (((id2) & 0x1fff) << 16);
> + cf->can_id = id | CAN_EFF_FLAG;
> + } else {
> + id = ((id2 & (CAN_SFF_MASK << 2)) >> 2);
> + cf->can_id = id;
> + }
> +
> + if (id2 & PCH_ID2_DIR)
> + cf->can_id |= CAN_RTR_FLAG;
> +
> + cf->can_dlc = get_can_dlc((ioread32(&priv->regs->
> + ifregs[0].mcont)) & 0xF);
> +

Using the idX value several times looks very nice!

> + for (i = 0; i < cf->can_dlc; i += 2) {
> + data_reg = ioread16(&priv->regs->ifregs[0].
> + data[i / 2]);
> + cf->data[i] = data_reg & 0xff;
> + cf->data[i + 1] = (data_reg >> 8) & 0xff;

The & 0xff in not needed "data" is 8 bit wide.

> + }
>
> netif_receive_skb(skb);
> rcv_pkts++;
> - goto RX_NEXT;
> - }
> - if (!(reg & CAN_IF_MCONT_NEWDAT))
> - goto RX_NEXT;
> -
> - skb = alloc_can_skb(priv->ndev, &cf);
> - if (!skb)
> - return -ENOMEM;
> -
> - /* Get Received data */
> - ide = ((ioread32(&priv->regs->if1_id2)) & CAN_ID2_XTD) >> 14;
> - if (ide) {
> - id = (ioread32(&priv->regs->if1_id1) & 0xffff);
> - id |= (((ioread32(&priv->regs->if1_id2)) &
> - 0x1fff) << 16);
> - cf->can_id = (id & CAN_EFF_MASK) | CAN_EFF_FLAG;
> - } else {
> - id = (((ioread32(&priv->regs->if1_id2)) &
> - (CAN_SFF_MASK << 2)) >> 2);
> - cf->can_id = (id & CAN_SFF_MASK);
> - }
> + stats->rx_packets++;
> + quota--;
> + stats->rx_bytes += cf->can_dlc;
>
> - rtr = (ioread32(&priv->regs->if1_id2) & CAN_ID2_DIR);
> - if (rtr) {
> - cf->can_dlc = 0;
> - cf->can_id |= CAN_RTR_FLAG;
> - } else {
> - cf->can_dlc = ((ioread32(&priv->regs->if1_mcont)) &
> - 0x0f);
> + pch_fifo_thresh(priv, obj_num);
> }
> + obj_num++;
> + next_flag = 0;
> + } while (quota > 0);
>
> - for (i = 0, j = 0; i < cf->can_dlc; j++) {
> - reg = ioread32(&priv->regs->if1_dataa1 + j*4);
> - cf->data[i++] = cpu_to_le32(reg & 0xff);
> - if (i == cf->can_dlc)
> - break;
> - cf->data[i++] = cpu_to_le32((reg >> 8) & 0xff);
> - }
> + return rcv_pkts;
> +}
>
> - netif_receive_skb(skb);
> - rcv_pkts++;
> - stats->rx_packets++;
> - stats->rx_bytes += cf->can_dlc;
> -
> - if (k < PCH_FIFO_THRESH) {
> - iowrite32(CAN_CMASK_RDWR | CAN_CMASK_CTRL |
> - CAN_CMASK_ARB, &priv->regs->if1_cmask);
> -
> - /* Clearing the Dir bit. */
> - pch_can_bit_clear(&priv->regs->if1_id2, CAN_ID2_DIR);
> -
> - /* Clearing NewDat & IntPnd */
> - pch_can_bit_clear(&priv->regs->if1_mcont,
> - CAN_IF_MCONT_INTPND);
> - pch_can_check_if_busy(&priv->regs->if1_creq, k);
> - } else if (k > PCH_FIFO_THRESH) {
> - pch_can_int_clr(priv, k);
> - } else if (k == PCH_FIFO_THRESH) {
> - int cnt;
> - for (cnt = 0; cnt < PCH_FIFO_THRESH; cnt++)
> - pch_can_int_clr(priv, cnt+1);
> - }
> -RX_NEXT:
> - /* Reading the messsage object from the Message RAM */
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if1_cmask);
> - pch_can_check_if_busy(&priv->regs->if1_creq, k + 1);
> - reg = ioread32(&priv->regs->if1_mcont);
> - }
> +static void pch_can_tx_complete(struct net_device *ndev, u32 int_stat)
> +{
> + struct pch_can_priv *priv = netdev_priv(ndev);
> + struct net_device_stats *stats = &(priv->ndev->stats);
> + u32 dlc;
>
> - return rcv_pkts;
> + can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_END - 1);
> + iowrite32(PCH_CMASK_RX_TX_GET | PCH_CMASK_CLRINTPND,
> + &priv->regs->ifregs[1].cmask);
> + dlc = get_can_dlc(ioread32(&priv->regs->ifregs[1].mcont) &
> + PCH_IF_MCONT_DLC);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, int_stat);
> + stats->tx_bytes += dlc;
> + stats->tx_packets++;
> + if (int_stat == PCH_TX_OBJ_END)
> + netif_wake_queue(ndev);
> }
> +
> static int pch_can_rx_poll(struct napi_struct *napi, int quota)

The function does tx, rx and error handling, better call it napi or just
poll.

> {
> struct net_device *ndev = napi->dev;
> struct pch_can_priv *priv = netdev_priv(ndev);
> - struct net_device_stats *stats = &(priv->ndev->stats);
> - u32 dlc;
> u32 int_stat;
> int rcv_pkts = 0;
^^^^

can be removed...if you remove the += below

> u32 reg_stat;
> - unsigned long flags;
>
> int_stat = pch_can_int_pending(priv);
> if (!int_stat)
> - return 0;
> + goto end;
>
> -INT_STAT:
> - if (int_stat == CAN_STATUS_INT) {
> + if ((int_stat == PCH_STATUS_INT) && (quota > 0)) {
^^^^^^^^^

quota should be >0 here, it's the first usage of quota in the function.

> reg_stat = ioread32(&priv->regs->stat);
> if (reg_stat & (PCH_BUS_OFF | PCH_LEC_ALL)) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> - if ((reg_stat & PCH_LEC_ALL) != PCH_LEC_ALL)
> + if (reg_stat & PCH_BUS_OFF ||
> + (reg_stat & PCH_LEC_ALL) != PCH_LEC_ALL) {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

can you combine these two ifs?

> pch_can_error(ndev, reg_stat);
> + quota--;
> + }
> }
>
> - if (reg_stat & PCH_TX_OK) {
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
> - pch_can_check_if_busy(&priv->regs->if2_creq,
> - ioread32(&priv->regs->intr));
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> + if (reg_stat & PCH_TX_OK)
> pch_can_bit_clear(&priv->regs->stat, PCH_TX_OK);
> - }

can the PCH_TX_OK and PCH_TX_OK related pch_can_bit_clear be combined
into a single pch_can_bit_clear?

>
> if (reg_stat & PCH_RX_OK)
> pch_can_bit_clear(&priv->regs->stat, PCH_RX_OK);
>
> int_stat = pch_can_int_pending(priv);
> - if (int_stat == CAN_STATUS_INT)
> - goto INT_STAT;
> }
>
> -MSG_OBJ:
> - if ((int_stat >= 1) && (int_stat <= PCH_RX_OBJ_NUM)) {
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> - rcv_pkts = pch_can_rx_normal(ndev, int_stat);
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> - if (rcv_pkts < 0)
> - return 0;
> - } else if ((int_stat > PCH_RX_OBJ_NUM) && (int_stat <= PCH_OBJ_NUM)) {
> - if (priv->msg_obj[int_stat - 1] == MSG_OBJ_TX) {
> - /* Handle transmission interrupt */
> - can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_NUM - 1);
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
> - iowrite32(CAN_CMASK_RX_TX_GET | CAN_CMASK_CLRINTPND,
> - &priv->regs->if2_cmask);
> - dlc = ioread32(&priv->regs->if2_mcont) &
> - CAN_IF_MCONT_DLC;
> - pch_can_check_if_busy(&priv->regs->if2_creq, int_stat);
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> - if (dlc > 8)
> - dlc = 8;
> - stats->tx_bytes += dlc;
> - stats->tx_packets++;
> - }
> + if (quota == 0)
> + goto end;
> +
> + if ((int_stat >= PCH_RX_OBJ_START) && (int_stat <= PCH_RX_OBJ_END)) {
> + rcv_pkts += pch_can_rx_normal(ndev, int_stat, quota);
...here... ^^

You cannot return -errno in pch_can_rx_normal, it would mess up quota
calculation.

> + quota -= rcv_pkts;
> + if (quota < 0)
> + goto end;

this should not happen.

> + } else if ((int_stat >= PCH_TX_OBJ_START) &&
> + (int_stat <= PCH_TX_OBJ_END)) {
> + /* Handle transmission interrupt */
> + pch_can_tx_complete(ndev, int_stat);
> }

Is it either RX or TX interrupt? Would it make sense to loop in the
"rx_poll" function to handle both RX and TX without exiting the NAPI
function?

> - int_stat = pch_can_int_pending(priv);
> - if (int_stat == CAN_STATUS_INT)
> - goto INT_STAT;
> - else if (int_stat >= 1 && int_stat <= 32)
> - goto MSG_OBJ;
> -
> +end:
> napi_complete(napi);
> pch_can_set_int_enables(priv, PCH_CAN_ALL);
>
> @@ -980,20 +801,18 @@ static int pch_set_bittiming(struct net_device *ndev)
> const struct can_bittiming *bt = &priv->can.bittiming;
> u32 canbit;
> u32 bepe;
> - u32 brp;
>
> /* Setting the CCE bit for accessing the Can Timing register. */
> - pch_can_bit_set(&priv->regs->cont, CAN_CTRL_CCE);
> -
> - brp = (bt->tq) / (1000000000/PCH_CAN_CLK) - 1;
> - canbit = brp & MSK_BITT_BRP;
> - canbit |= (bt->sjw - 1) << BIT_BITT_SJW;
> - canbit |= (bt->phase_seg1 + bt->prop_seg - 1) << BIT_BITT_TSEG1;
> - canbit |= (bt->phase_seg2 - 1) << BIT_BITT_TSEG2;
> - bepe = (brp & MSK_BRPE_BRPE) >> BIT_BRPE_BRPE;
> + pch_can_bit_set(&priv->regs->cont, PCH_CTRL_CCE);
> +
> + canbit = (bt->brp - 1) & PCH_MSK_BITT_BRP;
> + canbit |= (bt->sjw - 1) << PCH_BIT_SJW_SHIFT;
> + canbit |= (bt->phase_seg1 + bt->prop_seg - 1) << PCH_BIT_TSEG1_SHIFT;
> + canbit |= (bt->phase_seg2 - 1) << PCH_BIT_TSEG2_SHIFT;
> + bepe = ((bt->brp - 1) & PCH_MSK_BRPE_BRPE) >> PCH_BIT_BRPE_BRPE_SHIFT;
> iowrite32(canbit, &priv->regs->bitt);
> iowrite32(bepe, &priv->regs->brpe);
> - pch_can_bit_clear(&priv->regs->cont, CAN_CTRL_CCE);
> + pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_CCE);
>
> return 0;
> }
> @@ -1008,8 +827,8 @@ static void pch_can_start(struct net_device *ndev)
> pch_set_bittiming(ndev);
> pch_can_set_optmode(priv);
>
> - pch_can_tx_enable_all(priv);
> - pch_can_rx_enable_all(priv);
> + pch_can_set_tx_all(priv, 1);
> + pch_can_set_rx_all(priv, 1);
>
> /* Setting the CAN to run mode. */
> pch_can_set_run_mode(priv, PCH_CAN_RUN);
> @@ -1041,27 +860,18 @@ static int pch_can_open(struct net_device *ndev)
> struct pch_can_priv *priv = netdev_priv(ndev);
> int retval;
>
> - retval = pci_enable_msi(priv->dev);
> - if (retval) {
> - dev_info(&ndev->dev, "PCH CAN opened without MSI\n");
> - priv->use_msi = 0;
> - } else {
> - dev_info(&ndev->dev, "PCH CAN opened with MSI\n");
> - priv->use_msi = 1;
> - }
> -
> - /* Regsitering the interrupt. */
> + /* Regstering the interrupt. */
> retval = request_irq(priv->dev->irq, pch_can_interrupt, IRQF_SHARED,

Does this driver really support SHARED interrupts? The pch_can_interrupt
always return IRQ_HANDLED.

> ndev->name, ndev);
> if (retval) {
> - dev_err(&ndev->dev, "request_irq failed.\n");
> + netdev_err(ndev, "request_irq failed.\n");
> goto req_irq_err;
> }
>
> /* Open common can device */
> retval = open_candev(ndev);
> if (retval) {
> - dev_err(ndev->dev.parent, "open_candev() failed %d\n", retval);
> + netdev_err(ndev, "open_candev() failed %d\n", retval);
> goto err_open_candev;
> }
>
> @@ -1075,9 +885,6 @@ static int pch_can_open(struct net_device *ndev)
> err_open_candev:
> free_irq(priv->dev->irq, ndev);
> req_irq_err:
> - if (priv->use_msi)
> - pci_disable_msi(priv->dev);
> -
> pch_can_release(priv);
>
> return retval;
> @@ -1091,102 +898,68 @@ static int pch_close(struct net_device *ndev)
> napi_disable(&priv->napi);
> pch_can_release(priv);
> free_irq(priv->dev->irq, ndev);
> - if (priv->use_msi)
> - pci_disable_msi(priv->dev);
> close_candev(ndev);
> priv->can.state = CAN_STATE_STOPPED;
> return 0;
> }
>
> -static int pch_get_msg_obj_sts(struct net_device *ndev, u32 obj_id)
> -{
> - u32 buffer_status = 0;
> - struct pch_can_priv *priv = netdev_priv(ndev);
> -
> - /* Getting the message object status. */
> - buffer_status = (u32) pch_can_get_buffer_status(priv);
> -
> - return buffer_status & obj_id;
> -}
> -
> -
> static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
> {
> - int i, j;
> - unsigned long flags;
> struct pch_can_priv *priv = netdev_priv(ndev);
> struct can_frame *cf = (struct can_frame *)skb->data;
> - int tx_buffer_avail = 0;
> + int tx_obj_no = 0;
^^^^

There should be no need to initialize it with 0.

> + int i;
> + u32 id2;
>
> if (can_dropped_invalid_skb(ndev, skb))
> return NETDEV_TX_OK;
>
> - if (priv->tx_obj == (PCH_OBJ_NUM + 1)) { /* Point tail Obj */
> - while (pch_get_msg_obj_sts(ndev, (((1 << PCH_TX_OBJ_NUM)-1) <<
> - PCH_RX_OBJ_NUM)))
> - udelay(500);
> + if (priv->tx_obj == PCH_TX_OBJ_END) {

> + if (ioread32(&priv->regs->treq2) & 0xfc00)
^^^^^^
Please add a oneliner comment what this if checks, can you introduce a
define for this value?

> + netif_stop_queue(ndev);
>
> - priv->tx_obj = PCH_RX_OBJ_NUM + 1; /* Point head of Tx Obj ID */
> - tx_buffer_avail = priv->tx_obj; /* Point Tail of Tx Obj */
> + tx_obj_no = priv->tx_obj;
^^^^^^^^^^^^^^^^^^^^^^^^^
> + priv->tx_obj = PCH_TX_OBJ_START;
> } else {
> - tx_buffer_avail = priv->tx_obj;
> + tx_obj_no = priv->tx_obj;
^^^^^^^^^^^^^^^^^^^^^^^^^

can you move this before the if()?

> + priv->tx_obj++;
> }
> - priv->tx_obj++;
> -
> - /* Attaining the lock. */
> - spin_lock_irqsave(&priv->msgif_reg_lock, flags);
>
> - /* Reading the Msg Obj from the Msg RAM to the Interface register. */
> - iowrite32(CAN_CMASK_RX_TX_GET, &priv->regs->if2_cmask);
> - pch_can_check_if_busy(&priv->regs->if2_creq, tx_buffer_avail);
> -
> - /* Setting the CMASK register. */
> - pch_can_bit_set(&priv->regs->if2_cmask, CAN_CMASK_ALL);
> + /* Setting the CMASK register to set value */
> + iowrite32(PCH_CMASK_RX_TX_SET, &priv->regs->ifregs[1].cmask);
>
> /* If ID extended is set. */
> - pch_can_bit_clear(&priv->regs->if2_id1, 0xffff);
> - pch_can_bit_clear(&priv->regs->if2_id2, 0x1fff | CAN_ID2_XTD);
> if (cf->can_id & CAN_EFF_FLAG) {
> - pch_can_bit_set(&priv->regs->if2_id1, cf->can_id & 0xffff);
> - pch_can_bit_set(&priv->regs->if2_id2,
> - ((cf->can_id >> 16) & 0x1fff) | CAN_ID2_XTD);
> + iowrite32(cf->can_id & 0xffff, &priv->regs->ifregs[1].id1);
> + id2 = ((cf->can_id >> 16) & 0x1fff) | PCH_ID2_XTD;
> } else {
> - pch_can_bit_set(&priv->regs->if2_id1, 0);
> - pch_can_bit_set(&priv->regs->if2_id2,
> - (cf->can_id & CAN_SFF_MASK) << 2);
> + iowrite32(0, &priv->regs->ifregs[1].id1);
> + id2 = (cf->can_id & CAN_SFF_MASK) << 2;
> }
>
> + id2 |= PCH_ID_MSGVAL;
> +
> /* If remote frame has to be transmitted.. */
> if (cf->can_id & CAN_RTR_FLAG)
> - pch_can_bit_clear(&priv->regs->if2_id2, CAN_ID2_DIR);
> -
> - for (i = 0, j = 0; i < cf->can_dlc; j++) {
> - iowrite32(le32_to_cpu(cf->data[i++]),
> - (&priv->regs->if2_dataa1) + j*4);
> - if (i == cf->can_dlc)
> - break;
> - iowrite32(le32_to_cpu(cf->data[i++] << 8),
> - (&priv->regs->if2_dataa1) + j*4);
> - }
> -
> - can_put_echo_skb(skb, ndev, tx_buffer_avail - PCH_RX_OBJ_NUM - 1);
> + id2 &= ~PCH_ID2_DIR;

As far as I can see, there's no need to clear PCH_ID2_DIR.

> + else
> + id2 |= PCH_ID2_DIR;
>
> - /* Updating the size of the data. */
> - pch_can_bit_clear(&priv->regs->if2_mcont, 0x0f);
> - pch_can_bit_set(&priv->regs->if2_mcont, cf->can_dlc);
> + iowrite32(id2, &priv->regs->ifregs[1].id2);
>
> - /* Clearing IntPend, NewDat & TxRqst */
> - pch_can_bit_clear(&priv->regs->if2_mcont,
> - CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_INTPND |
> - CAN_IF_MCONT_TXRQXT);
> + /* Copy data to register */
> + for (i = 0; i < cf->can_dlc; i += 2) {
> + iowrite16(cf->data[i] | (cf->data[i + 1] << 8),
> + &priv->regs->ifregs[1].data[i / 2]);
> + }
>
> - /* Setting NewDat, TxRqst bits */
> - pch_can_bit_set(&priv->regs->if2_mcont,
> - CAN_IF_MCONT_NEWDAT | CAN_IF_MCONT_TXRQXT);
> + can_put_echo_skb(skb, ndev, tx_obj_no - PCH_RX_OBJ_END - 1);
>
> - pch_can_check_if_busy(&priv->regs->if2_creq, tx_buffer_avail);
> + /* Set the size of the data. Update if2_mcont*/
> + iowrite32(cf->can_dlc | PCH_IF_MCONT_NEWDAT | PCH_IF_MCONT_TXRQXT |
> + PCH_IF_MCONT_TXIE, &priv->regs->ifregs[1].mcont);
>
> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no);

Still we have the busy waiting in the TX path. Maybe you can move the
waiting before accessing the if[1] and remove the busy waiting here.

>
> return NETDEV_TX_OK;
> }
> @@ -1203,21 +976,90 @@ static void __devexit pch_can_remove(struct pci_dev *pdev)
> struct pch_can_priv *priv = netdev_priv(ndev);
>
> unregister_candev(priv->ndev);
> - free_candev(priv->ndev);
> pci_iounmap(pdev, priv->regs);
> + if (priv->use_msi)
> + pci_disable_msi(priv->dev);
> pci_release_regions(pdev);
> pci_disable_device(pdev);
> pci_set_drvdata(pdev, NULL);
> pch_can_reset(priv);
> + free_candev(priv->ndev);
> }
>
> #ifdef CONFIG_PM
> +static void pch_can_set_int_custom(struct pch_can_priv *priv)
> +{
> + /* Clearing the IE, SIE and EIE bits of Can control register. */
> + pch_can_bit_clear(&priv->regs->cont, PCH_CTRL_IE_SIE_EIE);
> +
> + /* Appropriately setting them. */
> + pch_can_bit_set(&priv->regs->cont,
> + ((priv->int_enables & PCH_MSK_CTRL_IE_SIE_EIE) << 1));
> +}
> +
> +/* This function retrieves interrupt enabled for the CAN device. */
> +static u32 pch_can_get_int_enables(struct pch_can_priv *priv)
> +{
> + /* Obtaining the status of IE, SIE and EIE interrupt bits. */
> + return (ioread32(&priv->regs->cont) & PCH_CTRL_IE_SIE_EIE) >> 1;
> +}
> +
> +static u32 pch_can_get_rxtx_ir(struct pch_can_priv *priv, u32 buff_num, u32 dir)
> +{
> + u32 ie, enable;
> +
> + if (dir)
> + ie = PCH_IF_MCONT_RXIE;
> + else
> + ie = PCH_IF_MCONT_TXIE;
> +
> + iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[dir].creq, buff_num);
> +
> + if (((ioread32(&priv->regs->ifregs[dir].id2)) & PCH_ID_MSGVAL) &&
> + ((ioread32(&priv->regs->ifregs[dir].mcont)) & ie))
> + enable = 1;
> + else
> + enable = 0;
> + return enable;
> +}
> +
> +static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
> + u32 buffer_num, u32 set)
> +{
> + iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
> + iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,
> + &priv->regs->ifregs[0].cmask);
> + if (set)
> + pch_can_bit_clear(&priv->regs->ifregs[0].mcont,
> + PCH_IF_MCONT_EOB);
> + else
> + pch_can_bit_set(&priv->regs->ifregs[0].mcont, PCH_IF_MCONT_EOB);
> +
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
> +}
> +
> +static u32 pch_can_get_rx_buffer_link(struct pch_can_priv *priv, u32 buffer_num)
> +{
> + u32 link;
> +
> + iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
> + pch_can_rw_msg_obj(&priv->regs->ifregs[0].creq, buffer_num);
> +
> + if (ioread32(&priv->regs->ifregs[0].mcont) & PCH_IF_MCONT_EOB)
> + link = 0;
> + else
> + link = 1;
> + return link;
> +}
> +
> static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
> {
> - int i; /* Counter variable. */
> - int retval; /* Return value. */
> + int i;
> + int retval;
> u32 buf_stat; /* Variable for reading the transmit buffer status. */
> - u32 counter = 0xFFFFFF;
> + u32 counter = PCH_COUNTER_LIMIT;
>
> struct net_device *dev = pci_get_drvdata(pdev);
> struct pch_can_priv *priv = netdev_priv(dev);
> @@ -1226,7 +1068,7 @@ static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
> pch_can_set_run_mode(priv, PCH_CAN_STOP);
>
> /* Indicate that we are aboutto/in suspend */
> - priv->can.state = CAN_STATE_SLEEPING;
> + priv->can.state = CAN_STATE_STOPPED;
>
> /* Waiting for all transmission to complete. */
> while (counter) {
> @@ -1240,31 +1082,24 @@ static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
> dev_err(&pdev->dev, "%s -> Transmission time out.\n", __func__);
>
> /* Save interrupt configuration and then disable them */
> - pch_can_get_int_enables(priv, &(priv->int_enables));
> + priv->int_enables = pch_can_get_int_enables(priv);
> pch_can_set_int_enables(priv, PCH_CAN_DISABLE);
>
> /* Save Tx buffer enable state */
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_TX)
> - pch_can_get_tx_enable(priv, i + 1,
> - &(priv->tx_enable[i]));
> - }
> + for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++)
> + priv->tx_enable[i] = pch_can_get_rxtx_ir(priv, i, PCH_TX_IFREG);
>
> /* Disable all Transmit buffers */
> - pch_can_tx_disable_all(priv);
> + pch_can_set_tx_all(priv, 0);
>
> /* Save Rx buffer enable state */
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_RX) {
> - pch_can_get_rx_enable(priv, i + 1,
> - &(priv->rx_enable[i]));
> - pch_can_get_rx_buffer_link(priv, i + 1,
> - &(priv->rx_link[i]));
> - }
> + for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
> + priv->rx_enable[i] = pch_can_get_rxtx_ir(priv, i, PCH_RX_IFREG);
> + priv->rx_link[i] = pch_can_get_rx_buffer_link(priv, i);
> }
>
> /* Disable all Receive buffers */
> - pch_can_rx_disable_all(priv);
> + pch_can_set_rx_all(priv, 0);
> retval = pci_save_state(pdev);
> if (retval) {
> dev_err(&pdev->dev, "pci_save_state failed.\n");
> @@ -1279,8 +1114,8 @@ static int pch_can_suspend(struct pci_dev *pdev, pm_message_t state)
>
> static int pch_can_resume(struct pci_dev *pdev)
> {
> - int i; /* Counter variable. */
> - int retval; /* Return variable. */
> + int i;
> + int retval;
> struct net_device *dev = pci_get_drvdata(pdev);
> struct pch_can_priv *priv = netdev_priv(dev);
>
> @@ -1312,23 +1147,16 @@ static int pch_can_resume(struct pci_dev *pdev)
> pch_can_set_optmode(priv);
>
> /* Enabling the transmit buffer. */
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_TX) {
> - pch_can_set_tx_enable(priv, i + 1,
> - priv->tx_enable[i]);
> - }
> - }
> + for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++)
> + pch_can_set_rxtx(priv, i, priv->tx_enable[i], PCH_TX_IFREG);
>
> /* Configuring the receive buffer and enabling them. */
> - for (i = 0; i < PCH_OBJ_NUM; i++) {
> - if (priv->msg_obj[i] == MSG_OBJ_RX) {
> - /* Restore buffer link */
> - pch_can_set_rx_buffer_link(priv, i + 1,
> - priv->rx_link[i]);
> -
> - /* Restore buffer enables */
> - pch_can_set_rx_enable(priv, i + 1, priv->rx_enable[i]);
> - }
> + for (i = PCH_TX_OBJ_START; i <= PCH_TX_OBJ_END; i++) {
> + /* Restore buffer link */
> + pch_can_set_rx_buffer_link(priv, i, priv->rx_link[i]);
> +
> + /* Restore buffer enables */
> + pch_can_set_rxtx(priv, i, priv->rx_enable[i], PCH_RX_IFREG);
> }
>
> /* Enable CAN Interrupts */
> @@ -1349,8 +1177,8 @@ static int pch_can_get_berr_counter(const struct net_device *dev,
> {
> struct pch_can_priv *priv = netdev_priv(dev);
>
> - bec->txerr = ioread32(&priv->regs->errc) & CAN_TEC;
> - bec->rxerr = (ioread32(&priv->regs->errc) & CAN_REC) >> 8;
> + bec->txerr = ioread32(&priv->regs->errc) & PCH_TEC;
> + bec->rxerr = (ioread32(&priv->regs->errc) & PCH_REC) >> 8;

try to minimize IO, only read errc once.

>
> return 0;
> }
> @@ -1361,7 +1189,6 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
> struct net_device *ndev;
> struct pch_can_priv *priv;
> int rc;
> - int index;
> void __iomem *addr;
>
> rc = pci_enable_device(pdev);
> @@ -1383,7 +1210,7 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
> goto probe_exit_ipmap;
> }
>
> - ndev = alloc_candev(sizeof(struct pch_can_priv), PCH_TX_OBJ_NUM);
> + ndev = alloc_candev(sizeof(struct pch_can_priv), PCH_TX_OBJ_END);
> if (!ndev) {
> rc = -ENOMEM;
> dev_err(&pdev->dev, "Failed alloc_candev\n");
> @@ -1399,7 +1226,7 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
> priv->can.do_get_berr_counter = pch_can_get_berr_counter;
> priv->can.ctrlmode_supported = CAN_CTRLMODE_LISTENONLY |
> CAN_CTRLMODE_LOOPBACK;
> - priv->tx_obj = PCH_RX_OBJ_NUM + 1; /* Point head of Tx Obj */
> + priv->tx_obj = PCH_TX_OBJ_START; /* Point head of Tx Obj */
>
> ndev->irq = pdev->irq;
> ndev->flags |= IFF_ECHO;
> @@ -1407,15 +1234,18 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
> pci_set_drvdata(pdev, ndev);
> SET_NETDEV_DEV(ndev, &pdev->dev);
> ndev->netdev_ops = &pch_can_netdev_ops;
> -
> priv->can.clock.freq = PCH_CAN_CLK; /* Hz */
> - for (index = 0; index < PCH_RX_OBJ_NUM;)
> - priv->msg_obj[index++] = MSG_OBJ_RX;
>
> - for (index = index; index < PCH_OBJ_NUM;)
> - priv->msg_obj[index++] = MSG_OBJ_TX;
> + netif_napi_add(ndev, &priv->napi, pch_can_rx_poll, PCH_RX_OBJ_END);
>
> - netif_napi_add(ndev, &priv->napi, pch_can_rx_poll, PCH_RX_OBJ_NUM);
> + rc = pci_enable_msi(priv->dev);
> + if (rc) {
> + dev_info(&ndev->dev, "PCH CAN opened without MSI\n");
> + priv->use_msi = 0;
> + } else {
> + dev_info(&ndev->dev, "PCH CAN opened with MSI\n");
> + priv->use_msi = 1;
> + }
>
> rc = register_candev(ndev);
> if (rc) {
> @@ -1426,7 +1256,8 @@ static int __devinit pch_can_probe(struct pci_dev *pdev,
> return 0;
>
> probe_exit_reg_candev:
> - free_candev(ndev);
> + if (priv->use_msi)
> + pci_disable_msi(priv->dev);
> probe_exit_alloc_candev:
> pci_iounmap(pdev, addr);
> probe_exit_ipmap:
> @@ -1458,6 +1289,6 @@ static void __exit pch_can_pci_exit(void)
> }
> module_exit(pch_can_pci_exit);
>
> -MODULE_DESCRIPTION("Controller Area Network Driver");
> +MODULE_DESCRIPTION("Intel EG20T PCH CAN(Controller Area Network) Driver");
> MODULE_LICENSE("GPL v2");
> MODULE_VERSION("0.94");

cheers, Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |

Attachments:

2010-11-19 06:19:03

[permalink] [raw]

Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On Tuesday, November 16, 2010 9:22 PM, Marc Kleine-Budde wrote :

Except the following, I have updated/resubmitted already .

>> static int pch_can_rx_poll(struct napi_struct *napi, int quota)
>> {
>> struct net_device *ndev = napi->dev;
>> struct pch_can_priv *priv = netdev_priv(ndev);
>> - struct net_device_stats *stats = &(priv->ndev->stats);
>> - u32 dlc;
>> u32 int_stat;
>> int rcv_pkts = 0;
^^^^
>can be removed...if you remove the += below
Since there is "goto" code, "=0" is better.

>> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no);
>Still we have the busy waiting in the TX path. Maybe you can move the
>waiting before accessing the if[1] and remove the busy waiting here.
I can't understand your saying.
For transmitting data, calling pch_can_rw_msg_obj is mandatory.

---
Thanks,

Tomoya MORINAGA
OKI SEMICONDUCTOR CO., LTD.

2010-11-22 05:05:56

[permalink] [raw]

Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On Friday, November 19, 2010 6:20 PM, Marc Kleine-Budde wrote :

>>>> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>>> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no);
>>> Still we have the busy waiting in the TX path. Maybe you can move the
>>> waiting before accessing the if[1] and remove the busy waiting here.
>> I can't understand your saying.
>> For transmitting data, calling pch_can_rw_msg_obj is mandatory.
>Yes, but the busy wait is not needed. It should be enough to do the
>busy-waiting _before_ accessing the if[1].

Do you mean we should create other pch_can_rw_msg_obj which doesn't have busy wait ?

---
Thanks,

Tomoya MORINAGA
OKI SEMICONDUCTOR CO., LTD.

2010-11-22 08:28:07

[permalink] [raw]

Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On 11/22/2010 06:05 AM, Tomoya MORINAGA wrote:
> On Friday, November 19, 2010 6:20 PM, Marc Kleine-Budde wrote :
>
>>>>> - spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
>>>>> + pch_can_rw_msg_obj(&priv->regs->ifregs[1].creq, tx_obj_no);
>>>> Still we have the busy waiting in the TX path. Maybe you can move the
>>>> waiting before accessing the if[1] and remove the busy waiting here.
>>> I can't understand your saying.
>>> For transmitting data, calling pch_can_rw_msg_obj is mandatory.
>> Yes, but the busy wait is not needed. It should be enough to do the
>> busy-waiting _before_ accessing the if[1].
>
> Do you mean we should create other pch_can_rw_msg_obj which doesn't have busy wait ?

ACK, and this non busy waiting is use in the TX path. But you add a busy
wait only function before accessing the if[1] in the TX path.

cheers, Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |

Attachments:

2010-11-24 00:09:22

[permalink] [raw]

Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On Monday, November 22, 2010 5:27 PM, Marc Kleine-Budde wrote:
>>>>> Still we have the busy waiting in the TX path. Maybe you can move the
>>>>> waiting before accessing the if[1] and remove the busy waiting here.
>>>> I can't understand your saying.
>>>> For transmitting data, calling pch_can_rw_msg_obj is mandatory.
>>> Yes, but the busy wait is not needed. It should be enough to do the
>>> busy-waiting _before_ accessing the if[1].
>>
>> Do you mean we should create other pch_can_rw_msg_obj which doesn't have busy wait ?
>ACK, and this non busy waiting is use in the TX path. But you add a busy
>wait only function before accessing the if[1] in the TX path.

The "busy waiting" of pch_can_rw_msg_obj is for next processing accesses to Message object.
If deleting this busy waiting, next processing can access to Message object, regardless previous transfer doesn't
complete yet.
Thus, I think, the "busy waiting" is necessary.

---
Thanks,

Tomoya MORINAGA
OKI SEMICONDUCTOR CO., LTD.

----- Original Message -----
From: "Marc Kleine-Budde" <[email protected]>
To: "Tomoya MORINAGA" <[email protected]>
Cc: <[email protected]>; <[email protected]>; "Samuel Ortiz" <[email protected]>;
<[email protected]>; <[email protected]>; "Christian Pellegrin" <[email protected]>;
<[email protected]>; <[email protected]>; "Masayuki Ohtake" <[email protected]>;
<[email protected]>; <[email protected]>; "David S. Miller" <[email protected]>; "Wolfgang Grandegger"
<[email protected]>; <[email protected]>
Sent: Monday, November 22, 2010 5:27 PM
Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

2010-11-24 12:34:38

[permalink] [raw]

Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On 11/24/2010 01:09 AM, Tomoya MORINAGA wrote:
> On Monday, November 22, 2010 5:27 PM, Marc Kleine-Budde wrote:
>>>>>> Still we have the busy waiting in the TX path. Maybe you can move the
>>>>>> waiting before accessing the if[1] and remove the busy waiting here.
>>>>> I can't understand your saying.
>>>>> For transmitting data, calling pch_can_rw_msg_obj is mandatory.
>>>> Yes, but the busy wait is not needed. It should be enough to do the
>>>> busy-waiting _before_ accessing the if[1].
>>>
>>> Do you mean we should create other pch_can_rw_msg_obj which doesn't have busy wait ?
>> ACK, and this non busy waiting is use in the TX path. But you add a busy
>> wait only function before accessing the if[1] in the TX path.
>
> The "busy waiting" of pch_can_rw_msg_obj is for next processing accesses to Message object.
> If deleting this busy waiting, next processing can access to Message object, regardless previous transfer doesn't
> complete yet.
> Thus, I think, the "busy waiting" is necessary.

Yes, it's necessary, but not where it is done currently.
Let me outline how I think the TX path should look like:

pch_xmit() {
take_care_about_flow_control();
prepare_can_frame_to_be_copied_to_tx_if();

/* most likely we don't have to wait here */
wait_until_tx_if_is_ready();

copy_can_frame_to_tx_if();

/* trigger tx in hardware */
send_tx_if_but_dont_do_busywait();

/* tx_if is busy now, but before we access it, we'll check tx_if is ready */
}

cheers, Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |

Attachments:

2010-11-25 12:03:49

[permalink] [raw]

Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On Wednesday, November 24, 2010 9:34 PM, Marc Kleine-Budde wrote :
>On 11/24/2010 01:09 AM, Tomoya MORINAGA wrote:
>> On Monday, November 22, 2010 5:27 PM, Marc Kleine-Budde wrote:
>>>>>>> Still we have the busy waiting in the TX path. Maybe you can move the
>>>>>>> waiting before accessing the if[1] and remove the busy waiting here.
>>>>>> I can't understand your saying.
>>>>>> For transmitting data, calling pch_can_rw_msg_obj is mandatory.
>>>>> Yes, but the busy wait is not needed. It should be enough to do the
>>>>> busy-waiting _before_ accessing the if[1].
>>>>
>>>> Do you mean we should create other pch_can_rw_msg_obj which doesn't have busy wait ?
>>> ACK, and this non busy waiting is use in the TX path. But you add a busy
>>> wait only function before accessing the if[1] in the TX path.
>>
>> The "busy waiting" of pch_can_rw_msg_obj is for next processing accesses to Message object.
>> If deleting this busy waiting, next processing can access to Message object, regardless previous transfer doesn't
>> complete yet.
>> Thus, I think, the "busy waiting" is necessary.
>
>Yes, it's necessary, but not where it is done currently.
>Let me outline how I think the TX path should look like:
>
>pch_xmit() {
> take_care_about_flow_control();
> prepare_can_frame_to_be_copied_to_tx_if();
>
> /* most likely we don't have to wait here */
> wait_until_tx_if_is_ready();
>
> copy_can_frame_to_tx_if();
>
> /* trigger tx in hardware */
> send_tx_if_but_dont_do_busywait();
>
> /* tx_if is busy now, but before we access it, we'll check tx_if is ready */
>}

This Tx path also has Read-Modify-Write for MessageRAM access.
Do you mean Tx path shouldn't have Read-Modify-Write ?

---
Thanks,

Tomoya MORINAGA
OKI SEMICONDUCTOR CO., LTD.

2010-11-25 12:08:52

[permalink] [raw]

Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On 11/25/2010 01:03 PM, Tomoya MORINAGA wrote:
> On Wednesday, November 24, 2010 9:34 PM, Marc Kleine-Budde wrote :
>> On 11/24/2010 01:09 AM, Tomoya MORINAGA wrote:
>>> On Monday, November 22, 2010 5:27 PM, Marc Kleine-Budde wrote:
>>>>>>>> Still we have the busy waiting in the TX path. Maybe you can move the
>>>>>>>> waiting before accessing the if[1] and remove the busy waiting here.
>>>>>>> I can't understand your saying.
>>>>>>> For transmitting data, calling pch_can_rw_msg_obj is mandatory.
>>>>>> Yes, but the busy wait is not needed. It should be enough to do the
>>>>>> busy-waiting _before_ accessing the if[1].
>>>>>
>>>>> Do you mean we should create other pch_can_rw_msg_obj which doesn't have busy wait ?
>>>> ACK, and this non busy waiting is use in the TX path. But you add a busy
>>>> wait only function before accessing the if[1] in the TX path.
>>>
>>> The "busy waiting" of pch_can_rw_msg_obj is for next processing accesses to Message object.
>>> If deleting this busy waiting, next processing can access to Message object, regardless previous transfer doesn't
>>> complete yet.
>>> Thus, I think, the "busy waiting" is necessary.
>>
>> Yes, it's necessary, but not where it is done currently.
>> Let me outline how I think the TX path should look like:
>>
>> pch_xmit() {
>> take_care_about_flow_control();
>> prepare_can_frame_to_be_copied_to_tx_if();
>>
>> /* most likely we don't have to wait here */
>> wait_until_tx_if_is_ready();
>>
>> copy_can_frame_to_tx_if();
>>
>> /* trigger tx in hardware */
>> send_tx_if_but_dont_do_busywait();
>>
>> /* tx_if is busy now, but before we access it, we'll check tx_if is ready */
>> }
>
> This Tx path also has Read-Modify-Write for MessageRAM access.
> Do you mean Tx path shouldn't have Read-Modify-Write ?

Why do you Read-Modify-Write for TX? Naively speaking you just need to
push your Data into a Mail/IF/Whatever and push the send button.

Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |

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2010-11-25 12:34:15

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Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On Thursday, November 25, 2010 9:08 PM, Marc Kleine-Budde wrote :
> Why do you Read-Modify-Write for TX? Naively speaking you just need to
> push your Data into a Mail/IF/Whatever and push the send button.

I see.
I will implement this.

--
Thanks,

Tomoya MORINAGA
OKI SEMICONDUCTOR CO., LTD.

2010-11-25 12:40:15

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Subject: Re: [PATCH net-next-2.6 v3] can: Topcliff: PCH_CAN driver: Add Flow control,

On 11/25/2010 01:34 PM, Tomoya MORINAGA wrote:
> On Thursday, November 25, 2010 9:08 PM, Marc Kleine-Budde wrote :
>> Why do you Read-Modify-Write for TX? Naively speaking you just need to
>> push your Data into a Mail/IF/Whatever and push the send button.
>
> I see.
> I will implement this.

With "naively speaking", I mean I haven't looked at the Datasheet, maybe
in the real world with real hardware it's needed to do a RMW.

regard, Marc

--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |

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