Hello,
On 2014-07-01 19:54, Tobias Jakobi wrote:
Marek Szyprowski wrote:
On 2014-07-01 10:52, Tobias Jakobi wrote:
I think you had a similar patch in the tizen tree, but according to
Tomasz Figa, it was considered a hack. I don't quite see how this is
different.
Also, if I have been following the discussion correctly, then the
powerdomain issue essentially is about the question which SoC block
needs the LCD0 domain and how the proper power on/off sequences should
look like.
At least the mixer power issue, which I pointed out some time ago, seems
to be deal with now:
https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm-exynos.git/commit/?h=exynos-drm-next&id=381be025ac1a6dc8efebdf146ced0d4a6007f77b
Well, that patch solves power on/off sequence issue with mixer and hdmi,
but it didn't solve the issue with additional managing of power domain
on/off. You can check that if you remove always on property, system will
freeze when hdmi cable is connected for the second time. I've investigated
it for some time, but right now I didn't find any 100% reliable solution
other than keeping the power domain enabled all the time. At least for
now, this patch lets you use HDMI without any stability issues.
Hmm, I have also applied a similar hack to force TV and LCD0 pd on on my
system, but I didn't experience this behaviour (cable reconnecting).
Guess I have to recheck with some more recent tree to make sure.
I've only found that there are still at least 2 issues with power domains.
One is Mixer/Video Processor dependency on LCD0 domain, second is the
proper
power on/off sequence of HDMI/Mixer and TV domain. Forcing both domains to
'always on' workarounds both issues for now. Right now I have no better
idea.
I had the impression that the patch from above, plus this one
https://git.kernel.org/cgit/linux/kernel/git/daeinki/drm-exynos.git/commit/?h=exynos-drm-next&id=245f98f269714c08dc6d66d021d166cf36059bc4
were supposed to fix these issues. I haven't tested them yet, because of
lack of time, but Rahul's patch appears to fix mixer poweroff, and
Inki's patch the sequencing (VP, Mixer and last but not least, the HDMI).
You can check it directly from the git branch I've prepared:
https://git.linaro.org/people/marek.szyprowski/linux-srpol.git/shortlog/refs/heads/v3.16-odroid
If you disable this always-on property from tv pd domain (you can keep lcd0
domain enabled to simplify things), the system will freeze. I really have
no idea how to fix this.
Later, once the proper sequence is found we can remove those properties
from Odroid DTS.
I dunno, because you would have to support the property to the end of
time then, even though it's not used anymore. Isn't that the kind of
thing that shouldn't end up in DT bindings specs?
I think that there have been recently similar issue with one of Exyno5 SoCs,
where one of the domain has been removed from DTS just to keep it enabled
all the time (assuming that bootloader left it enabled). See commit
8b3ca983a69ab28bab257bdbaa9eaa1b8830d7b7 ("ARM: dts: Remove g2d_pd node for
exynos5420"). So this property can be used for that case too.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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