Re: [PATCH RESEND v2 4/5] iommu/tegra-smmu: Rework tegra_smmu_probe_device()

[Guillaume Tucker]

On 10/02/2021 08:20, Nicolin Chen wrote:
> Hi Guillaume,
> 
> On Sat, Feb 06, 2021 at 01:40:13PM +0000, Guillaume Tucker wrote:
>>> It'd be nicer if I can get both logs of the vanilla kernel (failing)
>>> and the commit-reverted version (passing), each applying this patch.
>>
>> Sure, I've run 3 jobs:
>>
>> * v5.11-rc6 as a reference, to see the original issue:
>>   https://lava.collabora.co.uk/scheduler/job/3187848
>>
>> * + your debug patch:
>>   https://lava.collabora.co.uk/scheduler/job/3187849
>>
>> * + the "breaking" commit reverted, passing the tests:
>>   https://lava.collabora.co.uk/scheduler/job/3187851
> 
> Thanks for the help!
> 
> I am able to figure out what's probably wrong, yet not so sure
> about the best solution at this point.
> 
> Would it be possible for you to run one more time with another
> debugging patch? I'd like to see the same logs as previous:
> 1. Vanilla kernel + debug patch
> 2. Vanilla kernel + Reverted + debug patch

As it turns out, next-20210210 is passing all the tests again so
it looks like this got fixed in the meantime:

  https://lava.collabora.co.uk/scheduler/job/3210192
  https://lava.collabora.co.uk/results/3210192/0_igt-kms-tegra

And here's a more extensive list of IGT tests on next-20210211,
all the regressions have been fixed:

  https://kernelci.org/test/plan/id/60254c42f51df36be53abe62/


I haven't run a reversed bisection to find the fix, but I guess
it wouldn't be too hard to find out what happened by hand anyway.
I see the drm/tegra/for-5.12-rc1 tag has been merged into
linux-next, maybe that solved the issue?

FYI I've also run some jobs with your debug patch and with the
breaking patch reverted:

  https://lava.collabora.co.uk/scheduler/job/3210245
  https://lava.collabora.co.uk/scheduler/job/3210596

Meanwhile I'll see what can be done to improve the automated
bisection so if there are new IGT regressions they would get
reported earlier.  I guess it would have saved us all some time
if it had been bisected in December.

Thanks,
Guillaume