On 2018-11-06 11:14 a.m., David Francis wrote: > 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> Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> Harry > 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; > _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
