Hi Tomasz, On 8 July 2014 21:04, Tomasz Figa <t.figa@xxxxxxxxxxx> wrote: > Hi Rahul, > > On 07.07.2014 15:37, Rahul Sharma wrote: >> Hi Andrej, Inki, >> >> On 18 June 2014 12:06, Rahul Sharma <rahul.sharma@xxxxxxxxxxx> wrote: >>> Hi Andrej, >>> >>> On 18 June 2014 11:46, Andrzej Hajda <a.hajda@xxxxxxxxxxx> 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 <rahul.sharma@xxxxxxxxxxx> 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@xxxxxxxxxxxxxxx/msg31629.html) > > [PATCH] drm/exynos: fimd: Keep power enabled during fimd_bind > (https://lkml.org/lkml/2014/7/4/188) > > Best regards, > Tomasz > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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