Re: [PATCH 11/15] tty: msm_serial: use dmaengine_prep_slave_sg()

[Jiri Slaby]

On 15. 04. 24, 23:17, Marek Szyprowski wrote:
> On 05.04.2024 08:08, Jiri Slaby (SUSE) wrote:
> > This is a preparatory for the serial-to-kfifo switch. kfifo understands
> > only scatter-gatter approach, so switch to that.
> >
> > No functional change intended, it's just dmaengine_prep_slave_single()
> > inline expanded.
> >
> > And in this case, switch from dma_map_single() to dma_map_sg() too. This
> > needs struct msm_dma changes. I split the rx and tx parts into an union.
> > TX is now struct scatterlist, RX remains the old good phys-virt-count
> > triple.
> >
> > Signed-off-by: Jiri Slaby (SUSE) <jirislaby@xxxxxxxxxx>
> > Cc: Bjorn Andersson <andersson@xxxxxxxxxx>
> > Cc: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
> > Cc: linux-arm-msm@xxxxxxxxxxxxxxx
>
> I've just found that this patch broke UART operation on DragonBoard
> 410c. I briefly checked and didn't notice anything obviously wrong here,
> but the board stops transmitting any data from its serial port after the
> first message. I will try to analyze this issue a bit more tomorrow.

I double checked, but I see no immediate issues in the patch too. So 
please, if you can analyze this more…

thanks,
--
js
suse labs