From mboxrd@z Thu Jan 1 00:00:00 1970 From: Javier Martinez Canillas Subject: Re: [PATCH v3 00/19] Exynos SYSMMU (IOMMU) integration with DT and DMA-mapping subsystem Date: Tue, 20 Jan 2015 15:05:38 +0100 Message-ID: <54BE60B2.1030707@collabora.co.uk> References: <1416395748-10731-1-git-send-email-m.szyprowski@samsung.com> <1417514366.21830.22.camel@collabora.co.uk> <54818768.3080303@samsung.com> <54AC93E0.8010705@samsung.com> <54ACFD69.1020500@collabora.co.uk> <54AD0293.70909@samsung.com> <54AEB384.2040005@collabora.co.uk> <54B36C5A.6050109@samsung.com> <54B3F1B7.7090307@collabora.co.uk> <54B4ABFB.5000501@samsung.com> <54B5B5F6.3030607@collabora.co.uk> <54B5B721.4070309@collabora.co.uk> <54BE383B.5030505@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <54BE383B.5030505-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: Joonyoung Shim , Javier Martinez Canillas , Marek Szyprowski Cc: Rob Herring , "linux-samsung-soc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Shaik Ameer Basha , Arnd Bergmann , Inki Dae , David Wodhouse , Will Deacon , Tomasz Figa , Sjoerd Simons , linaro-mm-sig-cunTk1MwBs8s++Sfvej+rw@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Kukjin Kim , Laurent Pinchart , Kyungmin Park , Thierry Reding , Gustavo Padovan , Cho KyongHo , "linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" List-Id: iommu@lists.linux-foundation.org Hello Joonyoung, On 01/20/2015 12:12 PM, Joonyoung Shim wrote: >>> >>> I dug further on this issue and found that the cause is that the exynos_mixer >>> driver needs some clocks (CLK_HDMI and CLK_SCLK_HDMI) grabbed by exynos_hdmi >>> to be kept enabled after hdmi_poweroff (drivers/gpu/drm/exynos/exynos_hdmi.c). >>> >>> Otherwise, any access to mixer device registers leads to an imprecise external >>> abort error. The following change [0] to the Exynos DRM HDMI driver makes the >>> issue to not happen and I can successfully execute: >>> >>> # echo 1 > /sys/devices/platform/exynos-drm/graphics/fb0/blank >>> # echo 0 > /sys/devices/platform/exynos-drm/graphics/fb0/blank >>> > > Did you execute this operation repeatedly? Still i get error when i > execute this more than twice with your change [0]. > You mean that you are seeing the "Power domain power-domain disable failed" message but the system is not crashing or that you are still having the system crash? I've seen the former when running multiple times but I have not seen the crash when the hdmi clock is not disabled on hdmi_poweroff(). > Thanks. > Best regards, Javier