[PATCH v2] ARM: dts: exynos: Enable Mixer node for Exynos5800 Peach Pi machine

[Guillaume Tucker]

On 12/12/17 10:55, Marek Szyprowski wrote:
> Hi Guillaume,
> 
> On 2017-12-12 11:43, Guillaume Tucker wrote:
>> On 12/12/17 10:17, Marek Szyprowski wrote:
>>> Hi Krzysztof,
>>>
>>> On 2017-12-12 11:09, Krzysztof Kozlowski wrote:
>>>> On Tue, Dec 12, 2017 at 10:55 AM, Krzysztof Kozlowski <krzk at kernel.org> wrote:
>>>>> On Tue, Dec 12, 2017 at 8:42 AM, Javier Martinez Canillas
>>>>> <javierm at redhat.com> wrote:
>>>>>> Commit 1cb686c08d12 ("ARM: dts: exynos: Add status property to Exynos 542x
>>>>>> Mixer nodes") disabled the Mixer node by default in the DTSI and enabled
>>>>>> for each Exynos 542x DTS. But unfortunately it missed to enable it for the
>>>>>> Exynos5800 Peach Pi machine, since the 5800 is also an 542x SoC variant.
>>>>>>
>>>>>> Fixes: 1cb686c08d12 ("ARM: dts: exynos: Add status property to Exynos 542x Mixer nodes")
>>>>>> Signed-off-by: Javier Martinez Canillas <javierm at redhat.com>
>>>>>> Acked-by: Marek Szyprowski <m.szyprowski at samsung.com>
>>>>>>
>>>>>> ---
>>>>>>
>>>>>> Changes in v2:
>>>>>> - Remove RFT tag.
>>>>> Thanks guys! However I still would like to see a tested-by for this on
>>>>> Peach Pi (AFAIU, Marek's only acked the code/solution).
>>>> On the other hand I could just apply it for my for-next branch and
>>>> we'll see if it fixes kernel-ci boot tests... Not a nice way of
>>>> testing but apparently no one has Peach Pi.
>>>
>>> Frankly, I don't expect that this will solve the boot hang issue on PeachPi.
>>> However it should at least hide the unbalanced regulator issue.
>>
>> We have a peach-pi in our LAVA lab so I've tested it and
>> actually, it does fix the hang on v4.15-rc3:
>>
>>   https://lava.collabora.co.uk/scheduler/job/1019877
>>   https://lava.collabora.co.uk/scheduler/job/1019878
>>
>> I ran it twice and it booted both times.  I also ran the same
>> boot tests with the same kernel but the dtb from v4.15-rc3
>> without the fix to double check and these failed:
>>
>>   https://lava.collabora.co.uk/scheduler/job/1019879
>>   https://lava.collabora.co.uk/scheduler/job/1019880
>>
>>
>> Tested-by: Guillaume Tucker <guillaume.tucker at collabora.com>
>>
>>
>> Thanks for the fix!
> 
> Well, thanks for the test! It proves that there the boot failure is
> caused by an issue somewhere in the error path of Exynos DRM, Analogix
> DP, Simple Panel or other drivers.
> 
> This patch simply hides it by fixing the source issue of the Exynos
> DRM initialization failure. :-)
> 
> I hope Javier will be able to investigate the discussed hang issue
> later, as fixing it is also imho important.

Sure.  This device tree change is needed to get HDMI to work so
it's still a fix for that.  Also it's good to know that nothing
else breaks when the driver issue is "hidden".  Might be worth
testing on -next as well as it might help spot any new issues
that haven't been merged in mainline yet, or in general give
another data point.

Guillaume