Re: commit 271e1b86e691 is breaking DMA uart on SoCFPGA

[Alexander Kochetkov]

Hello, here comments from Shawn Lin:

19 ÑÐÐÑ. 2016 Ð., Ð 9:46, Shawn Lin <shawn.lin@xxxxxxxxxxxxxxxxxxx> ÐÐÐÐÑÐÐ(Ð):

Seriously review the patch again, commit 271e1b86e691 "dmaengine:
pl330: add quirk for broken no flushp" has not chance to break
the platforms which don't add quirk inside the dts stuff.
as well as the other works from rockchip.

But refer to Boojin Kim's patch,
dmaengine: pl330: support burst mode for dev-to-mem and mem-to-dev transmit

may some platforms can't support multi-burst? If that's the case,
the been-broken driver should limit the maxburst.

2016-02-17 14:12 GMT+03:00 Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>:
>
> Hi,
>
> On Thursday, February 11, 2016 02:27:51 PM Vinod Koul wrote:
>> On Wed, Feb 10, 2016 at 03:56:17PM -0600, Dinh Nguyen wrote:
>> > Hi Vinod,
>> >
>> > It appears that commit 271e1b86e691 "dmaengine: pl330: add quirk for
>> > broken no flushp" is breaking uart dma on SoCFPGA. This commit is in
>> > linux-next(next-20160210).
>> >
>> > Doing a bisect pointed to commit 271e1b86e691, but I had to also revert
>> > the following commits (86a8ce7d4103 "dmaengine: pl330: add max burst for
>> > dmaengine") and (848e9776fee4 "dmaengine: pl330: support burst mode for
>> > dev-to-mem and mem-to-dev transmit") as well because the build would
>> > fail if I only revert 271e1b86e691.
>> >
>> > The SoCFPGA platform is being tested on Olof's board farm and is failing
>> > multi_v7_defconfig build because the PL330 DMA is enabled in this defconfig.
>> >
>> > After doing reverts of those 3 commits, the socfpga platform is able
>> > boot completely again with multi_v7_defconfig.
>>
>> Okay I am removing this topic from next. Also I can drop the series unless
>> someone sends me a fix in couple of days..
>
> I've noticed that these commits also break UART DMA on Samsung Exynos4412
> SoCs (I got similar bisection results as Dinh when I've noticed issue
> with next-20160211 kernel).
>
> Caesar, please keep me on Cc: for potential fix(es) / revised patches
> (I'll be happy to test them).
>
> Best regards,
> --
> Bartlomiej Zolnierkiewicz
> Samsung R&D Institute Poland
> Samsung Electronics
>