From ba05b237372bad82533d1f717569d1d817ff3c27 Mon Sep 17 00:00:00 2001 From: John Serock Date: Thu, 13 Oct 2011 06:42:01 -0400 Subject: Platform: Detect samsung laptop quirk when initial level is zero This patch depends on the "Platform: Brightness quirk for samsung laptop driver" patch from Jason Stubbs. This patch adds a check for an initial brightness level of 0; if the level is 0, this patch changes the brightness level to 1 before the driver attempts to detect the brightness quirk. The Samsung N150 netbook experiences the brightness quirk. Without Jason's patch, the only brightness levels available on the N150 are 0, 1, and 8. This patch ensures that, when the initial brightness level is 0, the samsang-laptop driver detects the brightness quirk on the N150, thereby making brightness levels 0 through 8 available. Signed-off-by: John Serock Acked-by: Jason Stubbs Signed-off-by: Matthew Garrett --- drivers/platform/x86/samsung-laptop.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/platform/x86/samsung-laptop.c') diff --git a/drivers/platform/x86/samsung-laptop.c b/drivers/platform/x86/samsung-laptop.c index 1e436ebdcffc..31ddd57e8ca7 100644 --- a/drivers/platform/x86/samsung-laptop.c +++ b/drivers/platform/x86/samsung-laptop.c @@ -404,8 +404,9 @@ static int get_brightness(struct backlight_device *bd) static void check_for_stepping_quirk(void) { - u8 initial_level = read_brightness(); + u8 initial_level; u8 check_level; + u8 orig_level = read_brightness(); /* * Some laptops exhibit the strange behaviour of stepping toward @@ -414,6 +415,11 @@ static void check_for_stepping_quirk(void) * around in set_brightness. */ + if (orig_level == 0) + set_brightness(1); + + initial_level = read_brightness(); + if (initial_level <= 2) check_level = initial_level + 2; else @@ -427,7 +433,7 @@ static void check_for_stepping_quirk(void) pr_info("enabled workaround for brightness stepping quirk\n"); } - set_brightness(initial_level); + set_brightness(orig_level); } static int update_status(struct backlight_device *bd) -- cgit v1.2.3