2021-09-21 01:33:57

by Alain Volmat

[permalink] [raw]
Subject: [PATCH 3/4] i2c: stm32f7: stop dma transfer in case of NACK

In case of receiving a NACK, the dma transfer should be stopped
to avoid feeding data into the FIFO.
Also ensure to properly return the proper error code and avoid
waiting for the end of the dma completion in case of
error happening during the transmission.

Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")

Signed-off-by: Alain Volmat <[email protected]>
---
drivers/i2c/busses/i2c-stm32f7.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index ad3459a3bc5e..50d5ae81d227 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -1493,6 +1493,7 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
{
struct stm32f7_i2c_dev *i2c_dev = data;
struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
+ struct stm32_i2c_dma *dma = i2c_dev->dma;
void __iomem *base = i2c_dev->base;
u32 status, mask;
int ret = IRQ_HANDLED;
@@ -1518,6 +1519,10 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",
__func__, f7_msg->addr);
writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
+ if (i2c_dev->use_dma) {
+ stm32f7_i2c_disable_dma_req(i2c_dev);
+ dmaengine_terminate_all(dma->chan_using);
+ }
f7_msg->result = -ENXIO;
}

@@ -1533,7 +1538,7 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
/* Clear STOP flag */
writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);

- if (i2c_dev->use_dma) {
+ if (i2c_dev->use_dma && !f7_msg->result) {
ret = IRQ_WAKE_THREAD;
} else {
i2c_dev->master_mode = false;
@@ -1546,7 +1551,7 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
if (f7_msg->stop) {
mask = STM32F7_I2C_CR2_STOP;
stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
- } else if (i2c_dev->use_dma) {
+ } else if (i2c_dev->use_dma && !f7_msg->result) {
ret = IRQ_WAKE_THREAD;
} else if (f7_msg->smbus) {
stm32f7_i2c_smbus_rep_start(i2c_dev);
--
2.25.1


2021-09-23 08:40:05

by Pierre Yves MORDRET

[permalink] [raw]
Subject: Re: [PATCH 3/4] i2c: stm32f7: stop dma transfer in case of NACK

Hi Alain

Look good to me

Reviewed-by: Pierre-Yves MORDRET <[email protected]>

Regards

On 9/20/21 5:21 PM, Alain Volmat wrote:
> In case of receiving a NACK, the dma transfer should be stopped
> to avoid feeding data into the FIFO.
> Also ensure to properly return the proper error code and avoid
> waiting for the end of the dma completion in case of
> error happening during the transmission.
>
> Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
>
> Signed-off-by: Alain Volmat <[email protected]>
> ---
> drivers/i2c/busses/i2c-stm32f7.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index ad3459a3bc5e..50d5ae81d227 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -1493,6 +1493,7 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
> {
> struct stm32f7_i2c_dev *i2c_dev = data;
> struct stm32f7_i2c_msg *f7_msg = &i2c_dev->f7_msg;
> + struct stm32_i2c_dma *dma = i2c_dev->dma;
> void __iomem *base = i2c_dev->base;
> u32 status, mask;
> int ret = IRQ_HANDLED;
> @@ -1518,6 +1519,10 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
> dev_dbg(i2c_dev->dev, "<%s>: Receive NACK (addr %x)\n",
> __func__, f7_msg->addr);
> writel_relaxed(STM32F7_I2C_ICR_NACKCF, base + STM32F7_I2C_ICR);
> + if (i2c_dev->use_dma) {
> + stm32f7_i2c_disable_dma_req(i2c_dev);
> + dmaengine_terminate_all(dma->chan_using);
> + }
> f7_msg->result = -ENXIO;
> }
>
> @@ -1533,7 +1538,7 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
> /* Clear STOP flag */
> writel_relaxed(STM32F7_I2C_ICR_STOPCF, base + STM32F7_I2C_ICR);
>
> - if (i2c_dev->use_dma) {
> + if (i2c_dev->use_dma && !f7_msg->result) {
> ret = IRQ_WAKE_THREAD;
> } else {
> i2c_dev->master_mode = false;
> @@ -1546,7 +1551,7 @@ static irqreturn_t stm32f7_i2c_isr_event(int irq, void *data)
> if (f7_msg->stop) {
> mask = STM32F7_I2C_CR2_STOP;
> stm32f7_i2c_set_bits(base + STM32F7_I2C_CR2, mask);
> - } else if (i2c_dev->use_dma) {
> + } else if (i2c_dev->use_dma && !f7_msg->result) {
> ret = IRQ_WAKE_THREAD;
> } else if (f7_msg->smbus) {
> stm32f7_i2c_smbus_rep_start(i2c_dev);
>

--
--
~ Py MORDRET
--

2021-11-30 09:28:05

by Wolfram Sang

[permalink] [raw]
Subject: Re: [PATCH 3/4] i2c: stm32f7: stop dma transfer in case of NACK

On Mon, Sep 20, 2021 at 05:21:31PM +0200, Alain Volmat wrote:
> In case of receiving a NACK, the dma transfer should be stopped
> to avoid feeding data into the FIFO.
> Also ensure to properly return the proper error code and avoid
> waiting for the end of the dma completion in case of
> error happening during the transmission.
>
> Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
>
> Signed-off-by: Alain Volmat <[email protected]>

Applied to for-current, thanks!


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