tree 5793be775bbb57b7bfe442be679ccf65e6e7d557
parent b620fec43eeeadb25d96e537fc06dddf59ebfd78
author Takashi Iwai <tiwai@suse.de> 1318585540 +0200
committer Greg Kroah-Hartman <gregkh@suse.de> 1321032919 -0800

drm/i915/panel: Always record the backlight level again (but cleverly)

commit f52c619a590fa75276c07dfcaf380dee53e4ea4c upstream.

The commit 47356eb67285014527a5ab87543ba1fae3d1e10a introduced a
mechanism to record the backlight level only at disabling time, but it
also introduced a regression.  Since intel_lvds_enable() may be called
without disabling (e.g. intel_lvds_commit() calls it unconditionally),
the backlight gets back to the last recorded value.  For example, this
happens when you dim the backlight, close the lid and open the lid,
then the backlight suddenly goes to the brightest.

This patch fixes the bug by recording the backlight level always
when changed via intel_panel_set_backlight().  And,
intel_panel_{enable|disable}_backlight() call the internal function not
to update the recorded level wrongly.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>