On Thu, Apr 30, 2015 at 8:44 AM, Kevin Hilman khilman@kernel.org wrote:
Krzysztof Kozlowski k.kozlowski@samsung.com writes:
2015-04-30 2:31 GMT+09:00 Kevin Hilman khilman@kernel.org:
Krzysztof Kozlowski k.kozlowski@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@samsung.com Reported-by: Javier Martinez Canillas javier.martinez@collabora.co.uk Fixes: 2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250") Cc: stable@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=1...
Er, yup. That would explain it. ;)
Sorry for the noise,
Well, noise or not, Exynos is still broken in mainline and was broken on -next for so long in different ways that bisecting it is a futile exercise in frustration.
It doesn't seem to show up with a trivial boot using only ramdisk, but when booting a real distro from disk, it certainly does.
For example:
http://arm-soc.lixom.net/bootlogs/mainline/v4.1-rc1-56-g3d99e3f/pi-arm-exyno...
Disabling CONFIG_DRM makes it boot reliably.
Arndale doesn't show it for me, but it also doesn't have working graphics.
-Olof