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

From: [email-masked] (Kevin Hilman)
Date: Wed, 29 Apr 2015 10:31:41 -0700

Krzysztof Kozlowski <[email-masked]> 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 <[email-masked]>
> Reported-by: Javier Martinez Canillas <[email-masked]>
> Fixes: 2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250")
> Cc: <[email-masked]>
>
> ---
>
> 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?

Kevin