2015-07-28 03:38:26

by Eddie Huang (黃智傑)

[permalink] [raw]
Subject: [PATCH] i2c: mediatek: fix transfer error handling

From: Liguo Zhang <[email protected]>

Reset i2c dma engine in hw init function.
When occur i2c ack error, mtk_i2c_irq may is twice,
first is the ack error interrupt, then the complete interrupt,
so i2c->irq_stat need keep the two interrupt value, and only
call complete() for the complete interrupt.

Signed-off-by: Liguo Zhang <[email protected]>
Signed-off-by: Eddie Huang <[email protected]>
---
drivers/i2c/busses/i2c-mt65xx.c | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index 9920eef..57d11b7 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -59,6 +59,7 @@
#define I2C_DMA_START_EN 0x0001
#define I2C_DMA_INT_FLAG_NONE 0x0000
#define I2C_DMA_CLR_FLAG 0x0000
+#define I2C_DMA_HARD_RST 0x0002

#define I2C_DEFAULT_SPEED 100000 /* hz */
#define MAX_FS_MODE_SPEED 400000
@@ -81,6 +82,7 @@ enum DMA_REGS_OFFSET {
OFFSET_INT_FLAG = 0x0,
OFFSET_INT_EN = 0x04,
OFFSET_EN = 0x08,
+ OFFSET_RST = 0x0c,
OFFSET_CON = 0x18,
OFFSET_TX_MEM_ADDR = 0x1c,
OFFSET_RX_MEM_ADDR = 0x20,
@@ -262,6 +264,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
writew(control_reg, i2c->base + OFFSET_CONTROL);
writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
+
+ writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
+ udelay(50);
+ writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
}

/*
@@ -550,16 +556,20 @@ err_exit:
static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
{
struct mtk_i2c *i2c = dev_id;
- u16 restart_flag = 0;
+ u16 intr_stat = 0;

- if (i2c->dev_comp->auto_restart)
- restart_flag = I2C_RS_TRANSFER;
+ intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
+ writew(intr_stat, i2c->base + OFFSET_INTR_STAT);

- i2c->irq_stat = readw(i2c->base + OFFSET_INTR_STAT);
- writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR
- | I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
+ /*
+ * when occurs i2c ack error, mtk_i2c_irq is called twice,
+ * first is the ack error interrupt, then the complete interrupt,
+ * i2c->irq_stat need keep the two interrupt value.
+ */
+ i2c->irq_stat |= intr_stat;

- complete(&i2c->msg_complete);
+ if (i2c->irq_stat & I2C_TRANSAC_COMP)
+ complete(&i2c->msg_complete);

return IRQ_HANDLED;
}
@@ -729,3 +739,4 @@ module_platform_driver(mtk_i2c_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
MODULE_AUTHOR("Xudong Chen <[email protected]>");
+MODULE_AUTHOR("Liguo Zhang <[email protected]>");
--
1.7.9.5


2015-07-31 11:01:01

by Wolfram Sang

[permalink] [raw]
Subject: Re: [PATCH] i2c: mediatek: fix transfer error handling

On Tue, Jul 28, 2015 at 11:38:05AM +0800, Eddie Huang wrote:
> From: Liguo Zhang <[email protected]>
>
> Reset i2c dma engine in hw init function.
> When occur i2c ack error, mtk_i2c_irq may is twice,
> first is the ack error interrupt, then the complete interrupt,
> so i2c->irq_stat need keep the two interrupt value, and only
> call complete() for the complete interrupt.
>
> Signed-off-by: Liguo Zhang <[email protected]>
> Signed-off-by: Eddie Huang <[email protected]>

Looks to me this patch needs to be split up into one patch per issue?
And doesn't it kill the auto_restart functionality? Sascha?

> ---
> drivers/i2c/busses/i2c-mt65xx.c | 25 ++++++++++++++++++-------
> 1 file changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> index 9920eef..57d11b7 100644
> --- a/drivers/i2c/busses/i2c-mt65xx.c
> +++ b/drivers/i2c/busses/i2c-mt65xx.c
> @@ -59,6 +59,7 @@
> #define I2C_DMA_START_EN 0x0001
> #define I2C_DMA_INT_FLAG_NONE 0x0000
> #define I2C_DMA_CLR_FLAG 0x0000
> +#define I2C_DMA_HARD_RST 0x0002
>
> #define I2C_DEFAULT_SPEED 100000 /* hz */
> #define MAX_FS_MODE_SPEED 400000
> @@ -81,6 +82,7 @@ enum DMA_REGS_OFFSET {
> OFFSET_INT_FLAG = 0x0,
> OFFSET_INT_EN = 0x04,
> OFFSET_EN = 0x08,
> + OFFSET_RST = 0x0c,
> OFFSET_CON = 0x18,
> OFFSET_TX_MEM_ADDR = 0x1c,
> OFFSET_RX_MEM_ADDR = 0x20,
> @@ -262,6 +264,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
> I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
> writew(control_reg, i2c->base + OFFSET_CONTROL);
> writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
> +
> + writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
> + udelay(50);
> + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
> }
>
> /*
> @@ -550,16 +556,20 @@ err_exit:
> static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
> {
> struct mtk_i2c *i2c = dev_id;
> - u16 restart_flag = 0;
> + u16 intr_stat = 0;
>
> - if (i2c->dev_comp->auto_restart)
> - restart_flag = I2C_RS_TRANSFER;
> + intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
> + writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
>
> - i2c->irq_stat = readw(i2c->base + OFFSET_INTR_STAT);
> - writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR
> - | I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
> + /*
> + * when occurs i2c ack error, mtk_i2c_irq is called twice,
> + * first is the ack error interrupt, then the complete interrupt,
> + * i2c->irq_stat need keep the two interrupt value.
> + */
> + i2c->irq_stat |= intr_stat;
>
> - complete(&i2c->msg_complete);
> + if (i2c->irq_stat & I2C_TRANSAC_COMP)
> + complete(&i2c->msg_complete);
>
> return IRQ_HANDLED;
> }
> @@ -729,3 +739,4 @@ module_platform_driver(mtk_i2c_driver);
> MODULE_LICENSE("GPL v2");
> MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
> MODULE_AUTHOR("Xudong Chen <[email protected]>");
> +MODULE_AUTHOR("Liguo Zhang <[email protected]>");
> --
> 1.7.9.5
>


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2015-08-04 06:13:57

by Eddie Huang (黃智傑)

[permalink] [raw]
Subject: Re: [PATCH] i2c: mediatek: fix transfer error handling

On Fri, 2015-07-31 at 13:00 +0200, Wolfram Sang wrote:
> On Tue, Jul 28, 2015 at 11:38:05AM +0800, Eddie Huang wrote:
> > From: Liguo Zhang <[email protected]>
> >
> > Reset i2c dma engine in hw init function.
> > When occur i2c ack error, mtk_i2c_irq may is twice,
> > first is the ack error interrupt, then the complete interrupt,
> > so i2c->irq_stat need keep the two interrupt value, and only
> > call complete() for the complete interrupt.
> >
> > Signed-off-by: Liguo Zhang <[email protected]>
> > Signed-off-by: Eddie Huang <[email protected]>
>
> Looks to me this patch needs to be split up into one patch per issue?
OK, I can split

> And doesn't it kill the auto_restart functionality? Sascha?

No. restart_flag already set in mtk_i2c_do_transfer() function.It is not
necessary check restart_flag again in mtk_i2c_irq(). It is simpler to
just read status bit and write back to clear interrupt status.

Eddie
Thanks

>
> > ---
> > drivers/i2c/busses/i2c-mt65xx.c | 25 ++++++++++++++++++-------
> > 1 file changed, 18 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
> > index 9920eef..57d11b7 100644
> > --- a/drivers/i2c/busses/i2c-mt65xx.c
> > +++ b/drivers/i2c/busses/i2c-mt65xx.c
> > @@ -59,6 +59,7 @@
> > #define I2C_DMA_START_EN 0x0001
> > #define I2C_DMA_INT_FLAG_NONE 0x0000
> > #define I2C_DMA_CLR_FLAG 0x0000
> > +#define I2C_DMA_HARD_RST 0x0002
> >
> > #define I2C_DEFAULT_SPEED 100000 /* hz */
> > #define MAX_FS_MODE_SPEED 400000
> > @@ -81,6 +82,7 @@ enum DMA_REGS_OFFSET {
> > OFFSET_INT_FLAG = 0x0,
> > OFFSET_INT_EN = 0x04,
> > OFFSET_EN = 0x08,
> > + OFFSET_RST = 0x0c,
> > OFFSET_CON = 0x18,
> > OFFSET_TX_MEM_ADDR = 0x1c,
> > OFFSET_RX_MEM_ADDR = 0x20,
> > @@ -262,6 +264,10 @@ static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
> > I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN;
> > writew(control_reg, i2c->base + OFFSET_CONTROL);
> > writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN);
> > +
> > + writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST);
> > + udelay(50);
> > + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST);
> > }
> >
> > /*
> > @@ -550,16 +556,20 @@ err_exit:
> > static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id)
> > {
> > struct mtk_i2c *i2c = dev_id;
> > - u16 restart_flag = 0;
> > + u16 intr_stat = 0;
> >
> > - if (i2c->dev_comp->auto_restart)
> > - restart_flag = I2C_RS_TRANSFER;
> > + intr_stat = readw(i2c->base + OFFSET_INTR_STAT);
> > + writew(intr_stat, i2c->base + OFFSET_INTR_STAT);
> >
> > - i2c->irq_stat = readw(i2c->base + OFFSET_INTR_STAT);
> > - writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR
> > - | I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT);
> > + /*
> > + * when occurs i2c ack error, mtk_i2c_irq is called twice,
> > + * first is the ack error interrupt, then the complete interrupt,
> > + * i2c->irq_stat need keep the two interrupt value.
> > + */
> > + i2c->irq_stat |= intr_stat;
> >
> > - complete(&i2c->msg_complete);
> > + if (i2c->irq_stat & I2C_TRANSAC_COMP)
> > + complete(&i2c->msg_complete);
> >
> > return IRQ_HANDLED;
> > }
> > @@ -729,3 +739,4 @@ module_platform_driver(mtk_i2c_driver);
> > MODULE_LICENSE("GPL v2");
> > MODULE_DESCRIPTION("MediaTek I2C Bus Driver");
> > MODULE_AUTHOR("Xudong Chen <[email protected]>");
> > +MODULE_AUTHOR("Liguo Zhang <[email protected]>");
> > --
> > 1.7.9.5
> >