From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kukjin Kim Subject: Re: [PATCH] ARM: dts: remove display power domain for exynos5420 Date: Wed, 16 Jul 2014 08:35:50 +0900 Message-ID: <53C5BAD6.5030603@samsung.com> References: <1402313299-18885-1-git-send-email-rahul.sharma@samsung.com> <53A12EA3.5010007@samsung.com> <53BC0F8F.4010106@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pa0-f47.google.com ([209.85.220.47]:56878 "EHLO mail-pa0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934275AbaGOXf5 (ORCPT ); Tue, 15 Jul 2014 19:35:57 -0400 In-Reply-To: Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Rahul Sharma Cc: Kukjin Kim , Andrzej Hajda , "devicetree@vger.kernel.org" , linux-samsung-soc , Tomasz Figa , sunil joshi , Inki Dae , "linux-arm-kernel@lists.infradead.org" On 07/14/14 18:09, Rahul Sharma wrote: > Hi Kukjin, > Hi Rahul, > Please consider this patch for your branch. This patch is important > for Display for Exynos5 boards. > OK, I will take this for exynos5420 display for 3.17...BTW I'm not sure this is a regression for 3.16 or not...if so, please let me know. Thanks, Kukjin > Regards, > Rahul Sharma. > > On 9 July 2014 17:00, Rahul Sharma wrote: >> Hi Tomasz, >> >> On 8 July 2014 21:04, Tomasz Figa wrote: >>> Hi Rahul, >>> >>> On 07.07.2014 15:37, Rahul Sharma wrote: >>>> Hi Andrej, Inki, >>>> >>>> On 18 June 2014 12:06, Rahul Sharma wrote: >>>>> Hi Andrej, >>>>> >>>>> On 18 June 2014 11:46, Andrzej Hajda wrote: >>>>>> On 06/17/2014 07:49 AM, Rahul Sharma wrote: >>>>>>> Hi All, >>>>>>> >>>>>>> Please review this patch. >>>>>>> >>>>>>> Regards, >>>>>>> Rahul Sharma >>>>>>> >>>>>>> On 9 June 2014 16:58, Rahul Sharma wrote: >>>>>>>> Display domain is removed due to instability issues. Explaining >>>>>>>> the problem below: >>>>>>>> >>>>>>>> exynos_init_late triggers the pm_genpd_poweroff_unused which >>>>>>>> powers off the unused power domains. This call hits before >>>>>>>> the trigger to deferred probes. >>>>>>>> >>>>>>>> DRM DP Panel defers the probe due to supply get failure. By the >>>>>>>> time, deferred probe is scheduled again, Display Power Domain is >>>>>>>> powered off by pm_genpd_poweroff_unused. >>>>>>>> >>>>>>>> FIMD and DP drivers are accessing registers during Probe and Bind >>>>>>>> callbacks. If display domain is enabled/disabled around register >>>>>>>> accesses, display domain gets unstable and we are getting Power >>>>>>>> Domain Disable fail notification. Increasing the Timeout also >>>>>>>> didn't help. >>>>>> >>>>>> As I understand the problem is that fimd and dp drivers access hw >>>>>> registers without enabling power domain. So the proper solution is to >>>>>> fix these drivers. >>>>> >>>>> That is also a problem but I fixed those accesses in my local kernel before >>>>> hitting this issue. If we do register accesses in FIMD/DP probe/bind we >>>>> observes "Prefetch abort" exception. But here the problem is that 'DP >>>>> domain disable' starts failing if we enable/disable multiple times. >>>>> >>>>>> >>>>>> Btw. there are already patches removing hw access from probe/bind of >>>>>> fimd. I guess removing also hw access from dp probe/bind could be a good >>>>>> solution. >>>>> >>>>> Please let me know the links for posted patches. I will test with those patches. >>>> >>>> Is there any update on this? Please share the patches which fixes the >>>> above issue or avoid the above scenario of multiple PM Domain enable/disable. >>>> I will test them for exynos5 based boards. Otherwise we should get this change >>>> merged else display will remain broken for exynos5 based boards. >>> >>> Andrzej is on holidays right now, so he won't be able to reply in this >>> thread until he's back. Here are two patches I was able to find on the >>> related MLs that might be fixing the cause of your issues: >> >> Ok. thanks for the update. >> >> We should test with Ajay's patches which includes DP probe deferring >> based on availability of bridge chip. + >> >> few patches which cleanup register access in FIMD and DP probe/bind >> OR >> few patches to enable Display power domain and clocks just before the >> register access. As done in https://lkml.org/lkml/2014/7/4/188. >> >> Later solution results into display power domain enable failure in case of DRM >> probe defer. >> >> I am just curious if Andrej has some solution for the first approach which can >> be tested for defer probe and S2R scenarios. >> >> Regards, >> Rahul Sharma. >> >>> >>> [PATCH] drm/exynos: remove hardware overlays disable from fimd probe >>> (https://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/msg31629.html) >>> >>> [PATCH] drm/exynos: fimd: Keep power enabled during fimd_bind >>> (https://lkml.org/lkml/2014/7/4/188) From mboxrd@z Thu Jan 1 00:00:00 1970 From: kgene.kim@samsung.com (Kukjin Kim) Date: Wed, 16 Jul 2014 08:35:50 +0900 Subject: [PATCH] ARM: dts: remove display power domain for exynos5420 In-Reply-To: References: <1402313299-18885-1-git-send-email-rahul.sharma@samsung.com> <53A12EA3.5010007@samsung.com> <53BC0F8F.4010106@samsung.com> Message-ID: <53C5BAD6.5030603@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 07/14/14 18:09, Rahul Sharma wrote: > Hi Kukjin, > Hi Rahul, > Please consider this patch for your branch. This patch is important > for Display for Exynos5 boards. > OK, I will take this for exynos5420 display for 3.17...BTW I'm not sure this is a regression for 3.16 or not...if so, please let me know. Thanks, Kukjin > Regards, > Rahul Sharma. > > On 9 July 2014 17:00, Rahul Sharma wrote: >> Hi Tomasz, >> >> On 8 July 2014 21:04, Tomasz Figa wrote: >>> Hi Rahul, >>> >>> On 07.07.2014 15:37, Rahul Sharma wrote: >>>> Hi Andrej, Inki, >>>> >>>> On 18 June 2014 12:06, Rahul Sharma wrote: >>>>> Hi Andrej, >>>>> >>>>> On 18 June 2014 11:46, Andrzej Hajda wrote: >>>>>> On 06/17/2014 07:49 AM, Rahul Sharma wrote: >>>>>>> Hi All, >>>>>>> >>>>>>> Please review this patch. >>>>>>> >>>>>>> Regards, >>>>>>> Rahul Sharma >>>>>>> >>>>>>> On 9 June 2014 16:58, Rahul Sharma wrote: >>>>>>>> Display domain is removed due to instability issues. Explaining >>>>>>>> the problem below: >>>>>>>> >>>>>>>> exynos_init_late triggers the pm_genpd_poweroff_unused which >>>>>>>> powers off the unused power domains. This call hits before >>>>>>>> the trigger to deferred probes. >>>>>>>> >>>>>>>> DRM DP Panel defers the probe due to supply get failure. By the >>>>>>>> time, deferred probe is scheduled again, Display Power Domain is >>>>>>>> powered off by pm_genpd_poweroff_unused. >>>>>>>> >>>>>>>> FIMD and DP drivers are accessing registers during Probe and Bind >>>>>>>> callbacks. If display domain is enabled/disabled around register >>>>>>>> accesses, display domain gets unstable and we are getting Power >>>>>>>> Domain Disable fail notification. Increasing the Timeout also >>>>>>>> didn't help. >>>>>> >>>>>> As I understand the problem is that fimd and dp drivers access hw >>>>>> registers without enabling power domain. So the proper solution is to >>>>>> fix these drivers. >>>>> >>>>> That is also a problem but I fixed those accesses in my local kernel before >>>>> hitting this issue. If we do register accesses in FIMD/DP probe/bind we >>>>> observes "Prefetch abort" exception. But here the problem is that 'DP >>>>> domain disable' starts failing if we enable/disable multiple times. >>>>> >>>>>> >>>>>> Btw. there are already patches removing hw access from probe/bind of >>>>>> fimd. I guess removing also hw access from dp probe/bind could be a good >>>>>> solution. >>>>> >>>>> Please let me know the links for posted patches. I will test with those patches. >>>> >>>> Is there any update on this? Please share the patches which fixes the >>>> above issue or avoid the above scenario of multiple PM Domain enable/disable. >>>> I will test them for exynos5 based boards. Otherwise we should get this change >>>> merged else display will remain broken for exynos5 based boards. >>> >>> Andrzej is on holidays right now, so he won't be able to reply in this >>> thread until he's back. Here are two patches I was able to find on the >>> related MLs that might be fixing the cause of your issues: >> >> Ok. thanks for the update. >> >> We should test with Ajay's patches which includes DP probe deferring >> based on availability of bridge chip. + >> >> few patches which cleanup register access in FIMD and DP probe/bind >> OR >> few patches to enable Display power domain and clocks just before the >> register access. As done in https://lkml.org/lkml/2014/7/4/188. >> >> Later solution results into display power domain enable failure in case of DRM >> probe defer. >> >> I am just curious if Andrej has some solution for the first approach which can >> be tested for defer probe and S2R scenarios. >> >> Regards, >> Rahul Sharma. >> >>> >>> [PATCH] drm/exynos: remove hardware overlays disable from fimd probe >>> (https://www.mail-archive.com/linux-samsung-soc at vger.kernel.org/msg31629.html) >>> >>> [PATCH] drm/exynos: fimd: Keep power enabled during fimd_bind >>> (https://lkml.org/lkml/2014/7/4/188)