Amgpu's backlight update status function was returning 1 (an error value) when the backlight property was 0. This breaks users that assume 0 is a valid backlight value (which is a correct assumption) If the user passes in a backlight value of 0, tell them everything is fine, then write a value of 1 to hardware. Signed-off-by: David Francis <David.Francis@xxxxxxx> Bugzilla: https://bugs.freedesktop.org/108668 Fixes: 416615ea9578 ("drm/amd/display: set backlight level limit to 1") Cc: Suresh.Guttula@xxxxxxx Cc: Harry.Wentland@xxxxxxx Cc: Samantham@xxxxxxxxxx --- .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c index f8ec8a146663..131e6483d442 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c @@ -1567,21 +1567,23 @@ static int amdgpu_dm_backlight_update_status(struct backlight_device *bd) { struct amdgpu_display_manager *dm = bl_get_data(bd); + /* backlight_pwm_u16_16 parameter is in unsigned 32 bit, 16 bit integer + * and 16 bit fractional, where 1.0 is max backlight value. + * bd->props.brightness is 8 bit format and needs to be converted by + * scaling via copy lower byte to upper byte of 16 bit value. + */ + uint32_t brightness = bd->props.brightness * 0x101; + /* * PWM interperts 0 as 100% rather than 0% because of HW - * limitation for level 0.So limiting minimum brightness level + * limitation for level 0. So limiting minimum brightness level * to 1. */ if (bd->props.brightness < 1) - return 1; + brightness = 0x101; - /* backlight_pwm_u16_16 parameter is in unsigned 32 bit, 16 bit integer - * and 16 bit fractional, where 1.0 is max backlight value. - * bd->props.brightness is 8 bit format and needs to be converted by - * scaling via copy lower byte to upper byte of 16 bit value. - */ if (dc_link_set_backlight_level(dm->backlight_link, - (bd->props.brightness * 0x101), 0, 0)) + brightness, 0, 0)) return 0; else return 1; -- 2.17.1 _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
