On Tue, 2010-10-19 at 11:10 +0200, Aaron Sowry wrote: > Hi, > > The NV50 codepath in nouveau_backlight.c invariably sets max_brightness to > 1025, regardless of the chipset in question. The maximum brightness is not > 1025 for all NV50 chipsets (for example, by setting the brightness via ACPI > controls and peeking the brightness register, I find that the maximum > brightness level for my a8 card is 0x4001df67 although I am unsure of the > significance of the MSB). > > This means when anything manipulates the backlight using nouveau controls (in > my case, usually g-p-m), I get very low backlight brightnesses. 2 questions: > > 1) Is this a known problem, and has it been looked at before? My affected > laptop is a ThinkPad and I know that some Macbooks are also affected, so I > would be surprised if it isn't fairly common. > > 2) In the absence of a reliable way to determine a card's max_brightness by > peeking registers or similar, is some kind of mapping table in the code an > acceptable solution for assigning max_brightness values to certain chipsets? I have a question to you that's important first: if you fix nouveau's max_brightness level, can you actually properly change the brightness?
I have an eDP laptop that shows the same backlight level regardless of what's in that register. Ben. > > This has been discussed at some length on the RedHat bugzilla here: > https://bugzilla.redhat.com/show_bug.cgi?id=625171 > > Cheers, > Aaron > _______________________________________________ > Nouveau mailing list > [email protected] > http://lists.freedesktop.org/mailman/listinfo/nouveau _______________________________________________ Nouveau mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/nouveau
