ACK: [PATCH 1/1][Oneiric SRU] Platform: Detect samsung laptop quirk when initial level is zero

[Tim Gardner]

On 12/02/2011 02:17 PM, Seth Forshee wrote:
> From: John Serock<john.serock at gmail.com>
>
> 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<john.serock at gmail.com>
> Acked-by: Jason Stubbs<jasonbstubbs at gmail.com>
> Signed-off-by: Matthew Garrett<mjg at redhat.com>
>
> (cherry picked from commit ba05b237372bad82533d1f717569d1d817ff3c27)
> BugLink: http://bugs.launchpad.net/bugs/810093
> Signed-off-by: Seth Forshee<seth.forshee at canonical.com>
> ---
>   drivers/platform/x86/samsung-laptop.c |   10 ++++++++--
>   1 files changed, 8 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/platform/x86/samsung-laptop.c b/drivers/platform/x86/samsung-laptop.c
> index c32dc39..e553486 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)


-- 
Tim Gardner tim.gardner at canonical.com