[v1] Fix STM32 I2C dma operations

[PATCH 2/3] i2c: stm32f7: unmap DMA mapped buffer

Posted by Clément Le Goffic 6 months ago

Fix an issue where the mapped DMA buffer was not unmapped.

Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
---
 drivers/i2c/busses/i2c-stm32f7.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
index 973a3a8c6d4a..a05cac5ee9db 100644
--- a/drivers/i2c/busses/i2c-stm32f7.c
+++ b/drivers/i2c/busses/i2c-stm32f7.c
@@ -1622,6 +1622,8 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
 		if (i2c_dev->use_dma) {
 			stm32f7_i2c_disable_dma_req(i2c_dev);
 			dmaengine_terminate_async(dma->chan_using);
+			dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len,
+					 dma->dma_data_dir);
 		}
 		f7_msg->result = -ENXIO;
 	}
@@ -1642,6 +1644,8 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
 				dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);
 				stm32f7_i2c_disable_dma_req(i2c_dev);
 				dmaengine_terminate_async(dma->chan_using);
+				dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len,
+						 dma->dma_data_dir);
 				f7_msg->result = -ETIMEDOUT;
 			}
 		}

-- 
2.43.0

Re: [PATCH 2/3] i2c: stm32f7: unmap DMA mapped buffer

Posted by Alain Volmat 5 months, 2 weeks ago

Hi Clément,

thanks for the patch.

On Mon, Jun 16, 2025 at 10:53:55AM +0200, Clément Le Goffic wrote:
> Fix an issue where the mapped DMA buffer was not unmapped.
> 
> Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
> ---
>  drivers/i2c/busses/i2c-stm32f7.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
> index 973a3a8c6d4a..a05cac5ee9db 100644
> --- a/drivers/i2c/busses/i2c-stm32f7.c
> +++ b/drivers/i2c/busses/i2c-stm32f7.c
> @@ -1622,6 +1622,8 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
>  		if (i2c_dev->use_dma) {
>  			stm32f7_i2c_disable_dma_req(i2c_dev);
>  			dmaengine_terminate_async(dma->chan_using);
> +			dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len,
> +					 dma->dma_data_dir);
>  		}
>  		f7_msg->result = -ENXIO;
>  	}
> @@ -1642,6 +1644,8 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
>  				dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);
>  				stm32f7_i2c_disable_dma_req(i2c_dev);
>  				dmaengine_terminate_async(dma->chan_using);
> +				dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len,
> +						 dma->dma_data_dir);
>  				f7_msg->result = -ETIMEDOUT;
>  			}
>  		}
> 

Sounds good to me, however there might be an additional place to fix
within the function stm32f7_i2c_handle_isr_errs:
Could you also take care of the unmap in the error ITs handling ?

Regards,
Alain

> -- 
> 2.43.0
>

Re: [PATCH 2/3] i2c: stm32f7: unmap DMA mapped buffer

Posted by Clement LE GOFFIC 5 months, 2 weeks ago

On 6/26/25 11:03, Alain Volmat wrote:
> Hi Clément,
> 
> thanks for the patch.
> 
> On Mon, Jun 16, 2025 at 10:53:55AM +0200, Clément Le Goffic wrote:
>> Fix an issue where the mapped DMA buffer was not unmapped.
>>
>> Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
>> Signed-off-by: Clément Le Goffic <clement.legoffic@foss.st.com>
>> ---
>>   drivers/i2c/busses/i2c-stm32f7.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
>> index 973a3a8c6d4a..a05cac5ee9db 100644
>> --- a/drivers/i2c/busses/i2c-stm32f7.c
>> +++ b/drivers/i2c/busses/i2c-stm32f7.c
>> @@ -1622,6 +1622,8 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
>>   		if (i2c_dev->use_dma) {
>>   			stm32f7_i2c_disable_dma_req(i2c_dev);
>>   			dmaengine_terminate_async(dma->chan_using);
>> +			dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len,
>> +					 dma->dma_data_dir);
>>   		}
>>   		f7_msg->result = -ENXIO;
>>   	}
>> @@ -1642,6 +1644,8 @@ static irqreturn_t stm32f7_i2c_isr_event_thread(int irq, void *data)
>>   				dev_dbg(i2c_dev->dev, "<%s>: Timed out\n", __func__);
>>   				stm32f7_i2c_disable_dma_req(i2c_dev);
>>   				dmaengine_terminate_async(dma->chan_using);
>> +				dma_unmap_single(i2c_dev->dev, dma->dma_buf, dma->dma_len,
>> +						 dma->dma_data_dir);
>>   				f7_msg->result = -ETIMEDOUT;
>>   			}
>>   		}
>>
> 
> Sounds good to me, however there might be an additional place to fix
> within the function stm32f7_i2c_handle_isr_errs:
> Could you also take care of the unmap in the error ITs handling ?

Ack
> 
> Regards,
> Alain
> 
>> -- 
>> 2.43.0
>>