From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Date: Fri, 27 Mar 2015 19:21:26 +0000 Subject: Re: [RFT PATCHv2] drm/exynos: Enable DP clock to fix display on Exynos5250 and other Message-Id: <5515ADB6.6050204@collabora.co.uk> List-Id: References: <1427472488-21454-1-git-send-email-k.kozlowski@samsung.com> In-Reply-To: <1427472488-21454-1-git-send-email-k.kozlowski@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Krzysztof Kozlowski , Jingoo Han , Inki Dae , Joonyoung Shim , Seung-Woo Kim , Kyungmin Park , David Airlie , Kukjin Kim , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fbdev@vger.kernel.org Cc: Marek Szyprowski , Andrzej Hajda , stable@vger.kernel.org Hello Krzysztof, On 03/27/2015 05:08 PM, Krzysztof Kozlowski wrote: > 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 > Reported-by: Javier Martinez Canillas > Fixes: 2d2c9a8d0a4f ("ARM: dts: add display power domain for exynos5250") > Cc: > > --- > > This should fix issue reported by Javier [1][2]. > I tested this patch and does indeed solves both issues I reported The exynos-dp probe deferral does not make the display to not be working and also disabling and enabling the display with: with /sys/devices/platform/exynos-drm/graphics/fb0/blank works. Thanks a lot for fixing this issue. On an Exynos5250 Snow Chromebook: Tested-by: Javier Martinez Canillas Best regards, Javier