Re: [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@xxxxxxxxxx> wrote:
> > > > > On Tue, Dec 12, 2017 at 8:42 AM, Javier Martinez Canillas
> > > > > <javierm@xxxxxxxxxx> 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@xxxxxxxxxx>
> > > > > > Acked-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> > > > > >
> > > > > > ---
> > > > > >
> > > > > > 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:
> >
> > Â https://lava.collabora.co.uk/scheduler/job/1019877
> > Â 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:
> >
> > Â https://lava.collabora.co.uk/scheduler/job/1019879
> > Â https://lava.collabora.co.uk/scheduler/job/1019880
> >
> >
> > Tested-by: Guillaume Tucker <guillaume.tucker@xxxxxxxxxxxxx>
> >
> >
> > 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