Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753716AbbHDGN5 (ORCPT ); Tue, 4 Aug 2015 02:13:57 -0400 Received: from mailgw01.mediatek.com ([210.61.82.183]:40091 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1753089AbbHDGNz (ORCPT ); Tue, 4 Aug 2015 02:13:55 -0400 X-Listener-Flag: 11101 Message-ID: <1438668829.16626.4.camel@mtksdaap41> Subject: Re: [PATCH] i2c: mediatek: fix transfer error handling From: Eddie Huang To: Wolfram Sang CC: , Matthias Brugger , Liguo Zhang , Xudong Chen , Sascha Hauer , , , , Date: Tue, 4 Aug 2015 14:13:49 +0800 In-Reply-To: <20150731110045.GJ1522@katana> References: <1438054685-25214-1-git-send-email-eddie.huang@mediatek.com> <20150731110045.GJ1522@katana> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit MIME-Version: 1.0 X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3737 Lines: 104 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 > > > > 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 > > Signed-off-by: Eddie Huang > > 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 "); > > +MODULE_AUTHOR("Liguo Zhang "); > > -- > > 1.7.9.5 > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/