[RFT PATCH] drm/exynos: Enable DP clock to fix display on Exynos5250 and other

Kevin Hilman khilman at kernel.org
Thu Apr 30 08:44:49 PDT 2015


Krzysztof Kozlowski <k.kozlowski at samsung.com> writes:

> 2015-04-30 2:31 GMT+09:00 Kevin Hilman <khilman at kernel.org>:
>> Krzysztof Kozlowski <k.kozlowski at samsung.com> writes:
>>
>>> After adding display power domain for Exynos5250 in commit
>>> 2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250") the
>>> display on Chromebook Snow and others stopped working after boot.
>>>
>>> The reason for this suggested Andrzej Hajda: the DP clock was disabled.
>>> This clock is required by Display Port and is enabled by bootloader.
>>> However when FIMD driver probing was deferred, the display power domain
>>> was turned off. This effectively reset the value of DP clock enable
>>> register.
>>>
>>> When exynos-dp is later probed, the clock is not enabled and display is
>>> not properly configured:
>>>
>>> exynos-dp 145b0000.dp-controller: Timeout of video streamclk ok
>>> exynos-dp 145b0000.dp-controller: unable to config video
>>>
>>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski at samsung.com>
>>> Reported-by: Javier Martinez Canillas <javier.martinez at collabora.co.uk>
>>> Fixes: 2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250")
>>> Cc: <stable at vger.kernel.org>
>>>
>>> ---
>>>
>>> This should fix issue reported by Javier [1][2].
>>>
>>> Tested on Chromebook Snow (Exynos 5250). More testing would be great,
>>> especially on other Exynos 5xxx products.
>>
>> I hoped to try this on my exynos5 boards, but it doesn't seem to apply
>> to linux-next or to Linus' master branch.
>>
>> Are there some other dependencies here?
>
> It is already applied:
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1c363c7cccf64128087002b0779986ad16aff6dc

Er, yup.  That would explain it. ;)

Sorry for the noise,

Kevin



More information about the linux-arm-kernel mailing list