https://bugzilla.kernel.org/show_bug.cgi?id=15182
--- Comment #35 from Zhang Rui <rui.zh...@intel.com> 2010-04-20 03:11:11 --- (In reply to comment #34) > So when user gives a value of 1-15 ACPI Video does a lookup to values from > above array and somehow this makes things get really confused. Output of > /proc/acpi/video/VGA/LCDD appears to show these levels: > > levels: 1 4 7 10 13 16 20 23 26 29 32 36 41 46 50 56 > current: 56 > > Based on eeepc-laptop logic, I think those levels should be 1-15. > > If I am in fact understand this all then probably means buggy DSDT and needs > to > be resolved by BIOS update from ASUS.... or if that doesn't happen then needs > to be blacklisted in ACPI Video to force . > Very good findings. I think this is the root cause of the problem. The ACPI video driver wants to make use of the PBLG/PBLS method, but fails. And I total agree that this should be fixed in the BIOS, i.e. provide a meaningful _BCL package for PBLG/PBLS. > In mean time, using acpi_backlight=vendor seems the best option and let > eeepc-laptop or eeepc-wmi take control of backlight. > well, you're right, for this specific BIOS. But we don't want too many dmi quirks in the kernel. As win7 uses wmi driver instead of ACPI video driver, the problem may also exist in Windows XP/Vista, right? We probably should push Asus to upgrade their BIOS. --- Comment #36 from Rolf Leggewie <bugzilla.kernel....@rolf.leggewie.biz> 2010-06-02 08:55:32 --- I update to the 1103 BIOS and the nonlinearity problem is gone. The maximum brightness will be less if I don't pass the boot parameter, though. So, there is still some work left to be done, but it seems to be ASUS' responsibility. -- Configure bugmail: https://bugzilla.kernel.org/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug. ------------------------------------------------------------------------------ _______________________________________________ acpi-bugzilla mailing list acpi-bugzilla@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/acpi-bugzilla
