Re: [PATCH] spi: stm32: fix missing pointer assignment in case of dma chaining

[Antonio Quartulli <antonio@mandelbit.com>]

On 26/02/2026 17:46, Alain Volmat wrote:
> Hi,
> 
> On Tue, Feb 24, 2026 at 04:25:14PM +0100, Antonio Quartulli wrote:
>> Hi,
>>
>> On 24/02/2026 16:09, Alain Volmat wrote:
>>> Commit c4f2c05ab029 ("spi: stm32: fix pointer-to-pointer variables usage")
>>> introduced a regression since dma descriptors generated as part of the
>>> stm32_spi_prepare_rx_dma_mdma_chaining function are not well propagated
>>> to the caller function, leading to mdma-dma chaining being no more
>>> functional.
>>>
>>> Fixes: c4f2c05ab029 ("spi: stm32: fix pointer-to-pointer variables usage")
>>> Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
>>> ---
>>>    drivers/spi/spi-stm32.c | 3 +++
>>>    1 file changed, 3 insertions(+)
>>>
>>> diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c
>>> index b99de8c4cc99..33f211e159ef 100644
>>> --- a/drivers/spi/spi-stm32.c
>>> +++ b/drivers/spi/spi-stm32.c
>>> @@ -1625,6 +1625,9 @@ static int stm32_spi_prepare_rx_dma_mdma_chaining(struct stm32_spi *spi,
>>>    		return -EINVAL;
>>>    	}
>>> +	*rx_mdma_desc = _mdma_desc;
>>> +	*rx_dma_desc = _dma_desc;
>>> +
>>
>> Thanks for catching this!
>>
>> Indeed my fix lost the pointer-to-pointer logic, which was needed to pass
>> back the computed values.
>>
>> This patch looks good, but at this point I think you can also remove the
>> lines:
>>
>> 	_dma_desc = NULL;
>>
>> in the error paths above? Setting them to NULL makes no sense as they are
>> not going anywhere.
> 
> I agree that those lines can be removed. However my feeling is that this
> is not part of this fix since this is more about removing useless lines.
> If this is ok for you I will propose another patch on top of the current
> one for that purpose and without the Fixes on it.

I agree.

This fix gets my

Acked-by: Antonio Quartulli <antonio@mandelbit.com>

However, I'd let Mark (the maintainer) decide.

Regards,


-- 
Antonio Quartulli

CEO and Co-Founder
Mandelbit Srl
https://www.mandelbit.com