Re: [BUG] Serial/dma stall/failure after "dmaengine: fsl-edma: extract common fsl-edma code (no changes in behavior intended)"

[Vinod <vkoul@kernel.org>]

On 05-07-18, 18:23, Angelo Dureghello wrote:
> Hi Stafan,
> 
> On Thu, Jul 05, 2018 at 05:55:31PM +0200, Stefan Agner wrote:
> > Hi Vinod, Hi Angelo,
> > 
> > On 05.07.2018 14:45, Angelo Dureghello wrote:
> > > Hi Vinod,
> > > 
> > > On Thu, Jul 05, 2018 at 10:12:53AM +0200, Angelo Dureghello wrote:
> > >> Hi Vinod,
> > >>
> > >> On Thu, Jul 05, 2018 at 01:05:52PM +0530, Vinod wrote:
> > >> > On 04-07-18, 10:54, Krzysztof Kozlowski wrote:
> > >> > > Hi,
> > >> > >
> > >> > > The commit 6ad069123f03bebe4315dea13d44845854ca6043 ("dmaengine:
> > >> > > fsl-edma: extract common fsl-edma code (no changes in behavior
> > >> > > intended)"), even though marked as no changes in behavior intended...
> > >> > > make serial console with DMA broken after boot. The console just hangs
> > >> > > - is not responsive even to SysRq. Usually after finishing boot -
> > >> > > before or after login prompt. Sometimes login is allowed and then it
> > >> > > hangs during printing dmesg.
> > >> > >
> > >> > > Board: Toradex Colibri VF50 (NXP VF500, Cortex A5, serial configured
> > >> > > with DMA) on Iris Carrier.
> > >> >
> > >> > Angelo ?
> > >> >
> > >> sorry for this. As said i couldn't test it in any of those arm boards
> > >> but i take a look.
> > >>
> > >> The only code part that changes is the initial setting up of the registers.
> > >> I am checking that.
> > >>
> > >> Regards,
> > >> Angelo
> > >>
> > > 
> > > I cannot find anything obviously wrong.
> > > And i cannot test on Vybrid.
> > > I will try to get a Vybrid V50 board to test this issue. It would
> > > require some days and also i wil be 3 weeks off on July.
> > > 
> > > So please revert my patch. 
> > 
> > I did not found the issue quickly. But I must say that I gave up pretty
> > quickly. There are too many changes in a single patch which makes it
> > hard to figure out what could be wrong. I'd rather prefer if we could
> > drop that patch again and go through another review phase.
> > 
> > Angelo, as far as I can see the patch has not been sent to LKML or the
> > ARM mailing list. Especially since you do not have such a device it
> > would have been nice to also send it to the ARM mailing list...
> > 
> > Can you resend your last revision with CC to me/ARM mailing list?
> > 
> 
> Thanks for looking into it.
> 
> I have spent a lot of time on this patch and really would have 
> dma for Coldfire available. So, have ordered a Colibri / v50 board.
> 
> Should receive it in few days and should be able to debug this issue, 
> but as said, i will be off for some weeks so looks like it is probably
> better to revert the patch.
> 
> My initial submit was a separate driver, to avoid such issues where
> i cannot test, but it resulted in too much duplicated code.
> 
> Sure, i can send the full patch to you/arm with all the fixes included
> until now.

Okay dropped now from -next. I still keeping topic/fsl around and
collect other fixes for you guys to check.

One way would be to split to common patch into multiple patch and check
regression. That should help quickly identify the issue.

-- 
~Vinod