On Fri, 06 Nov 2015, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: > On 06-11-15 11:19, Jani Nikula wrote: >> On Thu, 05 Nov 2015, Hans de Goede <hdegoede@xxxxxxxxxx> wrote: >>> Hi, >>> >>> As discussed in the past, the i915 opregion code does not do the >>> right thing wrt the CADL field when there are more then 8 outputs, >>> this is causing issues on many different types of Asus laptops. >>> >>> This thread has details and a number of attempts to fix this: >>> >>> https://lkml.org/lkml/2014/2/11/1032 >>> >>> This is impacting many users, here is an incomplete list of bug reports: >>> >>> https://bugzilla.kernel.org/show_bug.cgi?id=70241 >>> https://bugzilla.kernel.org/show_bug.cgi?id=88941 >>> https://bugzilla.redhat.com/show_bug.cgi?id=1144866 >>> https://bugzilla.redhat.com/show_bug.cgi?id=1277785 >>> >>> And I'm pretty sure that is just the tip of the iceberg, some users >>> have even analyzed their BIOS AML code and come up with an AML >>> hack in an attempt to fix this: >>> >>> http://blog.yjwong.name/fixing-display-backlight-hotkeys-on-asus-n550jk/ >>> >>> It would be really great of someone from Intel could step up and start >>> working on a proper fix for this. >> >> Hans, thanks for bringing this up again. >> >> IIUC this would require something along the lines of: >> >> - Properly map acpi video bus children and DRM connectors in >> intel_didl_outputs(). This is likely the hardest part. Save the >> display ids in struct intel_connector. >> >> - Replace intel_setup_cadls() with functions to add/remove display ids >> from opregion CADL. >> >> - Call the above functions as part of the modeset sequence (either from >> intel_display.c or from the encoder hooks, whichever is best) to keep >> CADL up-to-date about active outputs. Here, getting DP MST right is >> probably the hard one. >> >> If the mapping goes wrong, and some id that used to be in CADL with the >> current code gets dropped, this may regress. That's the biggest risk, >> really. >> >> For the backlight/hotkey stuff, the minimal fix may be to keep the >> stupid static initialization of the CADL in intel_setup_cadls() like we >> have now, but ensuring the embedded displays are included in the list. > > This is what Aaron's first attempt at fixing this more or less did: > > https://lkml.org/lkml/2014/2/11/1032 > > Unless someone actually steps up to do a proper fix for this *now*, > maybe the i915 driver needs to incorporate a slightly revised / improved > version of that patch as a work around for now ? "now" took a long time, but there's this series to try now: https://patchwork.freedesktop.org/series/4783/ BR, Jani. -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
