Commit cab267c6 authored by Michael Hanselmann's avatar Michael Hanselmann Committed by Linus Torvalds
Browse files

[PATCH] powermac backlight fixes 



Fix a erroneous calculation of the legacy brightness values as reported by
Paul Collins.  Additionally, it moves the calculation of the negative value
in the radeonfb driver after the value check.

Signed-off-by: default avatarMichael Hanselmann <linux-kernel@hansmi.ch>
Acked-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: default avatarPaul Collins <paul@briny.ondioline.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 96febe9f

arch/powerpc/platforms/powermac/backlight.c

+12 −2
Original line number Diff line number Diff line
@@ -119,7 +119,14 @@ int pmac_backlight_set_legacy_brightness(int brightness) 
		down(&pmac_backlight->sem);

		props = pmac_backlight->props;

		props->brightness = brightness *

			props->max_brightness / OLD_BACKLIGHT_MAX;

			(props->max_brightness + 1) /

			(OLD_BACKLIGHT_MAX + 1);



		if (props->brightness > props->max_brightness)

			props->brightness = props->max_brightness;

		else if (props->brightness < 0)

			props->brightness = 0;



		props->update_status(pmac_backlight);

		up(&pmac_backlight->sem);
@@ -140,8 +147,11 @@ int pmac_backlight_get_legacy_brightness() 


		down(&pmac_backlight->sem);

		props = pmac_backlight->props;



		result = props->brightness *

			OLD_BACKLIGHT_MAX / props->max_brightness;

			(OLD_BACKLIGHT_MAX + 1) /

			(props->max_brightness + 1);



		up(&pmac_backlight->sem);

	}

	mutex_unlock(&pmac_backlight_mutex);

drivers/video/aty/radeon_backlight.c

+3 −3
Original line number Diff line number Diff line
@@ -40,14 +40,14 @@ static int radeon_bl_get_level_brightness(struct radeon_bl_privdata *pdata, 


	mutex_unlock(&info->bl_mutex);



	if (pdata->negative)

		rlevel = MAX_RADEON_LEVEL - rlevel;



	if (rlevel < 0)

		rlevel = 0;

	else if (rlevel > MAX_RADEON_LEVEL)

		rlevel = MAX_RADEON_LEVEL;



	if (pdata->negative)

		rlevel = MAX_RADEON_LEVEL - rlevel;



	return rlevel;

}