[PATCH v3 2/3] i2c: stm32f7: unmap DMA mapped buffer
Clement LE GOFFIC
clement.legoffic at foss.st.com
Thu Jul 3 09:19:05 UTC 2025
Hi Andi,
On 7/2/25 19:08, Andi Shyti wrote:
> Hi Clement,
>
> On Mon, Jun 30, 2025 at 02:55:14PM +0200, Clément Le Goffic wrote:
>> Fix an issue where the mapped DMA buffer was not unmapped.
>
> "Fix an issue..." is too generic. Can you be more specific? Where
> was it mapped? Where was it left unmapped?
>
> Please, do consider that the user needs to understand what
> happens in the patch without needing to look into the patch.
Ok sure I'll refine the commit message.
>
>> Fixes: 7ecc8cfde553 ("i2c: i2c-stm32f7: Add DMA support")
>> Acked-by: Alain Volmat <alain.volmat at foss.st.com>
>> Signed-off-by: Clément Le Goffic <clement.legoffic at foss.st.com>
>> ---
>> drivers/i2c/busses/i2c-stm32f7.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/i2c/busses/i2c-stm32f7.c b/drivers/i2c/busses/i2c-stm32f7.c
>> index e4aaeb2262d0..042386b4cabe 100644
>> --- a/drivers/i2c/busses/i2c-stm32f7.c
>> +++ b/drivers/i2c/busses/i2c-stm32f7.c
>> @@ -1554,6 +1554,8 @@ static irqreturn_t stm32f7_i2c_handle_isr_errs(struct stm32f7_i2c_dev *i2c_dev,
>> 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);
>> }
>>
>> i2c_dev->master_mode = false;
>> @@ -1622,6 +1624,8 @@ 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 +1646,8 @@ 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);
>
> Can't we use the dma_callback here, or similar? I see some
> similar patterns and I think the code can be improved.
Yes, it seems the code can be factorized.
I'll submit a new version with the factorization.
Best regards,
Clément
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