On Tue, 11 Nov 2014 12:30:38 -0800 "U. Artie Eoff" <ullysses.a.eoff@xxxxxxxxx> wrote: > A userspace brightness range that is larger than the hardware > brightness range does not have a 1:1 mapping and can result > in brightness != actual_brightness for some values. > > Expose a fixed brightness range of [0..1000] to userspace so > that all values can map 1:1 into the hardware brightness > range. This would assume that the hardware range is always > greater than 1000, otherwise we're right back to the original > issue. > > This patch is based on Jani Nikula's proposed change in the > referenced ML thread, except use the range [0..1000] instead; > which was recommended by Jesse Barnes for smoother backlight > transitions. > > Reference: http://lists.freedesktop.org/archives/intel-gfx/2014-November/055221.html > Signed-off-by: U. Artie Eoff <ullysses.a.eoff@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_panel.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_panel.c b/drivers/gpu/drm/i915/intel_panel.c > index 4d63839..f74f5f2 100644 > --- a/drivers/gpu/drm/i915/intel_panel.c > +++ b/drivers/gpu/drm/i915/intel_panel.c > @@ -1057,7 +1057,7 @@ static int intel_backlight_device_register(struct intel_connector *connector) > * Note: Everything should work even if the backlight device max > * presented to the userspace is arbitrarily chosen. > */ > - props.max_brightness = panel->backlight.max; > + props.max_brightness = 1000; > props.brightness = scale_hw_to_user(connector, > panel->backlight.level, > props.max_brightness); Yeah looks ok to me. I guess Jani has to ack it too. Reviewed-by: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx> -- Jesse Barnes, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx
