Re: Peach Pi/Pit boot failures in linux-next (was Re: [RFC PATCH 1/1] drm/exynos: Move platform drivers registration to module init)

[Javier Martinez Canillas <javier.martinez@collabora.co.uk>]

Hello Kevin,

On 11/21/2014 05:38 PM, Kevin Hilman wrote:
>> So, I see two different boot failures on the Peach Pi[t] Chromebooks:
>>
>> 1) next20141121 boot fails due snd-soc-snow
>>
>> Disabling CONFIG_SND_SOC_SNOW makes the boot to got a little further
>> but still fails with the second issue:
>>
>> 2) next20141121 boot hangs if unused clocks are disabled.
>>
>> I tried to root cause these two issues but didn't see anything evident
>> so I'll find a last known good commit and bisect. If anyone has an
>> idea of the possible causes for these issues that would be appreciated.
> 
> FWIW, in addition to the failures on 5800/peach-pi, I'm also seeing boot
> failures in next-20141121 on the exynos5420-arndale-octa[1].  Adding
> clk_ignore_unused gets things booting there as well.
> 
> What's interesting is that my exynos5422-odroid-xu3 is booting fine as
> well as the exynos5420-arndale and the exynos5410-odroid-xu (shown as
> exynos5410-smdk5410)
> 
> Whatever the issue, it definietly seems like a problem that was came
> through a driver/subsystem tree because that these boards are all
> booting fine with Kukjin's for-next, arm-soc/for-next and
> mainline/v3.18-rc5 (all with just plain exynos_defconfig, and without
> clk_ignore_unused.)  For example, just looking at peach-pi across all
> these trees[2], you can see that it's only failing in linux-next.
>

By bisecting I found that the commit introducing both regressions is:

ae43b32 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12")

By reverting ae43b32, next-20141121 boots with both CONFIG_SND_SOC_SNOW=y
and *without* clk_ignore_unused.

Krzysztof,

I see you are the author of the patch, maybe you can take a look why this
is causing regressions in some Exynos boards?

Thanks a lot and best regards,
Javier