On Monday, July 29, 2013 09:36:31 PM * SAMÍ * wrote: > Hi Rafael, > > > did you commit a full revert? Yes, but I left acpi_video_backlight_quirks() (in drivers/acpi/video_detect.c) that is used to decide what to do with _DOS. Can you please check if making that function always return 'false' makes any difference? Rafael > Because I am experiencing quite weird things in rc3. > Do we have a bug opened to discuss about it? > > Here is what I can observe: > 1) During boot, probably when loading the driver, backlight gets off (or > to a level low enough to make me feel it is off) > 2) When I am playing with my Fn+x keys, I am getting a completely full / > completely low brightness with no intermediate steps > 3) When I am playing with my Fn+x keys while gnome brightness settings > panel is open, I am recovering intermediate steps but the Fn+x keys > behavior is inverted (the key supposed to lower the brightness make it > increase and vice-versa. Note that the gnome brightness indicator also > gets inverted). > 4) Playing with the mouse on gnome brightness settings is working, > except that on the minimum level, backlight gets off > 5) Writing to /sys/class/backlight/intel_backlight/brightness works > > > Regards > > On 07/25/2013 02:57 PM, Rafael J. Wysocki wrote: > > On Thursday, July 25, 2013 03:34:10 PM Jani Nikula wrote: > >> On Thu, 25 Jul 2013, "Rafael J. Wysocki" <rjw@xxxxxxx> wrote: > >>> On Thursday, July 25, 2013 11:09:27 AM Jani Nikula wrote: > >>>> On Thu, 25 Jul 2013, "Rafael J. Wysocki" <rjw@xxxxxxx> wrote: > >>>>> Well, I wonder what about the appended (untested) patch? > >>>> Rafael, before going there, I've been trying to wrap my (poor, rusty > >>>> after vacation) head around > >>>> > >>>> commit 8c5bd7adb2ce47e6aa39d17b2375f69b0c0aa255 > >>>> Author: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> > >>>> Date: Thu Jul 18 02:08:06 2013 +0200 > >>>> > >>>> ACPI / video / i915: No ACPI backlight if firmware expects Windows 8 > >>>> > >>>> and I can't see how it could work. > >>> Well, if it didn't work, people wouldn't see either improvement or breakage > >>> from it, but they do see that, so it evidently works. :-) > >> I didn't claim it didn't work, just that *I* didn't see how it could. ;) > >> > >>>> First, the ACPI_VIDEO_SKIP_BACKLIGHT flag seems to be checked before > >>>> it's actually set anywhere. > >>> Are you sure about that? > >>> > >>> acpi_video_bus_add() is the .add() callback routine for acpi_video_bus which > >>> in fact is an ACPI driver (the naming sucks, but I didn't invent it). This > >>> means that acpi_video_bus_add() can only be called *after* acpi_video_bus > >>> has been registered with the ACPI subsystem (and the driver core). That > >>> is done by acpi_bus_register_driver() and, guess what?, this happens in > >>> __acpi_video_register(). So clearly, acpi_video_bus_add() *cannot* run before > >>> __acpi_video_register(). > >> Right. I totally missed the call within the ternary operator. Thanks for > >> the explanation, and apologies for the noise. > >> > >>>> Second, with i915 that has opregion support, __acpi_video_register() > >>>> should only ever get called once. Which means the acpi_walk_namespace() > >>>> with video_unregister_backlight() should never get called in register. > >>>> > >>>> Please enlighten me. > >>> Actually, that's correct, so we don't need the whole > >>> video_unregister_backlight() thing, calling acpi_video_backlight_quirks() would > >>> be sufficient. > >>> > >>> Ah, one more reason to do a full revert. I'm thinking, though, that I'll leave > >>> acpi_video_backlight_quirks() as is so that it can be used by > >>> acpi_video_bus_(start)|(stop)_devices(), because that doesn't seem to cause > >>> problems to happen. > >> I observe that for the regular non-quirk acpi_video_register() call, > >> acpi_video_backlight_quirks() won't be called during register, but it > >> will get called later. This might have subtle effects later on, don't > >> you think? > > Yes, it might, but after dropping ACPI_VIDEO_SKIP_BACKLIGHT it should be OK. > > > >> As to the original problem, and your patch in this thread, what do you > >> think about having another value in acpi_backlight kernel parameter for > >> it? Having an i915 module parameter to tell acpi to use or not use > >> quirks seems odd, since the i915 is not really taking over > >> anything. It's just passing the info on to acpi. > > I agree, I'm going to send a full revert in a while and we'll think what to > > do about all that later. > > > > Thanks, > > Rafael > > > > > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
