diff mbox series

i2c: mediatek: Disable i2c start_en and clear intr_stat brfore reset

Message ID 1622117044-7583-1-git-send-email-qii.wang@mediatek.com (mailing list archive)
State New, archived
Headers show
Series i2c: mediatek: Disable i2c start_en and clear intr_stat brfore reset | expand

Commit Message

Qii Wang (王琪) May 27, 2021, 12:04 p.m. UTC 
From: Qii Wang <qii.wang@mediatek.com>

The i2c controller driver do dma reset after transfer timeout,
but sometimes dma reset will trigger an unexpected DMA_ERR irq.
It will cause the i2c controller to continuously send interrupts
to the system and cause soft lock-up. So we need to disable i2c
start_en and clear intr_stat to stop i2c controller before dma
reset when transfer timeout.

Signed-off-by: Qii Wang <qii.wang@mediatek.com>
---
 drivers/i2c/busses/i2c-mt65xx.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Wolfram Sang May 27, 2021, 8:14 p.m. UTC | #1 
On Thu, May 27, 2021 at 08:04:04PM +0800, qii.wang@mediatek.com wrote:
> From: Qii Wang <qii.wang@mediatek.com>
> 
> The i2c controller driver do dma reset after transfer timeout,
> but sometimes dma reset will trigger an unexpected DMA_ERR irq.
> It will cause the i2c controller to continuously send interrupts
> to the system and cause soft lock-up. So we need to disable i2c
> start_en and clear intr_stat to stop i2c controller before dma
> reset when transfer timeout.
> 
> Signed-off-by: Qii Wang <qii.wang@mediatek.com>

Is there a suitable Fixes tag for this?
Qii Wang (王琪) May 28, 2021, 1:37 a.m. UTC | #2 
On Thu, 2021-05-27 at 22:14 +0200, Wolfram Sang wrote:
> On Thu, May 27, 2021 at 08:04:04PM +0800, qii.wang@mediatek.com wrote:
> > From: Qii Wang <qii.wang@mediatek.com>
> > 
> > The i2c controller driver do dma reset after transfer timeout,
> > but sometimes dma reset will trigger an unexpected DMA_ERR irq.
> > It will cause the i2c controller to continuously send interrupts
> > to the system and cause soft lock-up. So we need to disable i2c
> > start_en and clear intr_stat to stop i2c controller before dma
> > reset when transfer timeout.
> > 
> > Signed-off-by: Qii Wang <qii.wang@mediatek.com>
> 
> Is there a suitable Fixes tag for this?
> 

Can you help to add the following tag, thanks
Fixes: aafced673c06("i2c: mediatek: move dma reset before i2c reset")
Wolfram Sang May 28, 2021, 8:13 a.m. UTC | #3 
On Fri, May 28, 2021 at 09:37:43AM +0800, Qii Wang wrote:
> On Thu, 2021-05-27 at 22:14 +0200, Wolfram Sang wrote:
> > On Thu, May 27, 2021 at 08:04:04PM +0800, qii.wang@mediatek.com wrote:
> > > From: Qii Wang <qii.wang@mediatek.com>
> > > 
> > > The i2c controller driver do dma reset after transfer timeout,
> > > but sometimes dma reset will trigger an unexpected DMA_ERR irq.
> > > It will cause the i2c controller to continuously send interrupts
> > > to the system and cause soft lock-up. So we need to disable i2c
> > > start_en and clear intr_stat to stop i2c controller before dma
> > > reset when transfer timeout.
> > > 
> > > Signed-off-by: Qii Wang <qii.wang@mediatek.com>
> > 
> > Is there a suitable Fixes tag for this?
> > 
> 
> Can you help to add the following tag, thanks
> Fixes: aafced673c06("i2c: mediatek: move dma reset before i2c reset")

Added this tag and applied to for-current, thanks!
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c
index ea337ba..bfd80b2 100644
--- a/drivers/i2c/busses/i2c-mt65xx.c
+++ b/drivers/i2c/busses/i2c-mt65xx.c
@@ -479,6 +479,11 @@  static void mtk_i2c_clock_disable(struct mtk_i2c *i2c)
 static void mtk_i2c_init_hw(struct mtk_i2c *i2c)
 {
 	u16 control_reg;
+	u16 intr_stat_reg;
+
+	mtk_i2c_writew(i2c, I2C_CHN_CLR_FLAG, OFFSET_START);
+	intr_stat_reg = mtk_i2c_readw(i2c, OFFSET_INTR_STAT);
+	mtk_i2c_writew(i2c, intr_stat_reg, OFFSET_INTR_STAT);
 
 	if (i2c->dev_comp->apdma_sync) {
 		writel(I2C_DMA_WARM_RST, i2c->pdmabase + OFFSET_RST);