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

[Antonio Quartulli]

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@xxxxxxxxxxx>
> > > ---
> > >    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@xxxxxxxxxxxxx>

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

Regards,


--
Antonio Quartulli

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