On Thu, 2008-07-31 at 10:51 +0800, Jonathan Woithe wrote: > > > I'm trying to sort out the status of this myself. Is the > expectation > > > that your patches *with* the IGD work from Matthew/Hong should > mean that > > > Fujitsus implementing IGD should not need fujitsu-laptop in order > to > > > provide working software backlight brightness control? > > I think so. > > Ok. > > > > Or shouldn't Matthew/Hong's patchset be necessary with your patch > in > > > theory? > > Thomas' patch assigns the responsibility to acpi video driver or > > platform drivers when a laptop supports brightness/display switch > both > > via ACPI video extension and vendor specific control methods. > > > > brightness/display switch via ACPI video driver sometimes doesn't > work > > even if the ACPI control methods are available, and Matthew/Hong's > patch > > fixes this problem, on platforms with intel integrated graphics > cards. > > I see. > > > And now, we should root cause why acpi_video_backlight_support() > failed > > on this laptop. > > Agreed. > > > > so allowing fujitsu-laptop to co-exist with video.ko handling the > > > backlight (as your patches allow) is the right thing to do. > > > > sure, they will co-exist, but I don't think fujitsu-laptop should > handle > > the backlight stuff, unless it's explicitly stated via the boot > > parameter "acpi_backlight=vendor". > > For laptops with both ACPI video extensions and vendor specific > control > methods I agree with this. However, users of laptops which have only > vendor > specific control methods (of which the S7020 is one AFAIK) should not > have > to give any boot parameters for things to work for them. sure. In this case, acpi_video_backlight_support() returns false, and vendor driver will handle the backlight switching. > In other words, > "acpi_backlight=vendor" should only come into play when the machine > has the > ACPI video extensions. I am assuming that this is the intention since > that's what the current patches appear to do. Yes. > > Is there a canonical source for Matthew/Hong's patch? To totally wrap > this > up I would like to try the S7020 with Matthew/Hong+Thomas. > I doubt > Matthew/Hong's work is relevant to the S7020 given that it's 3+ years > old > now, but it's best to test these things early. Agree. I think Matthew/Hong's patch should have no effect on your laptops, and fujistu-laptop should handle the backlight switch as before. thanks, rui -- 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
