alistair23-linux/drivers/gpu
Keith Packard ca88479c1c drm/i915: Treat pre-gen4 backlight duty cycle value consistently
For i945 and earlier chips, the backlight frequency value had the low
bit (of 16) fixed to zero. The Pineview code path handled this by just
exposing the backlight range as 15 bits while other chips had the
backlight range limited to 0 .. 0xfffe.

This patch makes everyone take the pineview code path, providing 15
bits of backlight duty cycle range which seems more than sufficient to
me.

Daniel Mack reported that writing 1 to bit 0 of the duty cycle
register was causing problems on his Samsung X20 notebook, even when
the duty cycle value was less than the maximum backlight value. (He
tried a value of 29749 with max_brightness of 29750). This patch never
writes a '1' to that bit.

Signed-off-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reported-and-tested-by: Daniel Mack <zonque@gmail.com>
Cc: stable@kernel.org
2011-11-23 13:07:13 -08:00
..
drm drm/i915: Treat pre-gen4 backlight duty cycle value consistently 2011-11-23 13:07:13 -08:00
stub i915: select VIDEO_OUTPUT_CONTROL for ACPI_VIDEO 2011-04-13 09:10:25 +10:00
vga drivers/gpu/vga/vgaarb.c: add missing kfree 2011-11-22 20:21:10 +00:00
Makefile