On Thu, 2007-08-16 at 18:34 -0500, Ryan May wrote: > Hi, > > I recently updated the BIOS on my HP Pavilion dv2125nr laptop to F.34 > (to enable the virtualization instructions). Since I did this, the Fn > keys to control brightness have failed to work properly under Linux, > though they work fine before booting (ie. at Grub). Hitting the Fn keys > caused the brightness to change to the minimum possible. In fact, > /proc/acpi/video/VGA/LCD/brightness would show that the level was set to > 0 (though 20 was the lowest available). I was still able to control the > brightness manually via /proc interface however. > > My investigations seem to indicate that HP, in their wisdom, seem to > have removed the _BQC method from their BIOS code. It seems that the > ACPI code in Linux that handles the key events to change the brightness > use the _BQC method without checking for success, which explains why the > level being set was garbage. However, the /proc interface for > brightness seems to only use device->brightness->curr to get the current > level. Do you happen to see a _BCQ method in the DSDT instead? My HP nc6320 has that, and last time I looked, it seemed like it could plausibly be a Microsoft induced rename / typo, as this method is mentioned for getting brightness on a Windows Vista compatible box. Did the bios update also mention any fixes for Vista compatibility? -- Peter Clifton Electrical Engineering Division, Engineering Department, University of Cambridge, 9, JJ Thomson Avenue, Cambridge CB3 0FA Tel: +44 (0)7729 980173 - (No signal in the lab!) - 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
