Re: Bug report: MIPS CI20/jz4740-mmc DMA and PREEMPT_NONE

[Ezequiel Garcia]

On Wed, 17 Oct 2018 at 16:50, Aaro Koskinen <aaro.koskinen@xxxxxx> wrote:
>
> Hi,
>
> On Wed, Oct 17, 2018 at 03:38:07PM +0200, Mathieu Malaterre wrote:
> > Since CONFIG_PREEMPT has been 'y' since at least commit 0752f92934292
> > could you confirm that the original mmc driver (kernel from imgtech
> > people) did work ok with PREEMPT_NONE (sorry I did not do my homework)
> > ?
>
> Sorry, cannot confirm or test that. I have only used the mainline kernel
> on this board, since v4.5 or so with my own custom config which has
> been PREEMPT_NONE until now.
>

Aaro,

I spent some time today investigating this issue. I think this driver
has a broken pre-request/post-request implementation.

Will post some patches soon.

Thanks for the report,
-- 
Ezequiel GarcÃa, VanguardiaSur
www.vanguardiasur.com.ar