2015-11-09 8:17 GMT-02:00 Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>: > On Mon, 09 Nov 2015, "Shih-Yuan Lee (FourDollars)" <sylee@xxxxxxxxxxxxx> wrote: >> The PWM brightness level of Dell XPS 13 (2015) is from 10 to 937 however >> the sysfs brightness level always starts from 0 so it is better to use >> 927 as the sysfs maximum brightness level and it becomes easier to map >> from the PWM brightness level to the sysfs brightness level. > > We've been thinking we should provide a fixed range to userspace > instead. Say, 0-100. While not clearly stated, this reply and the further ones sound like a rejection to his patch. I'm not really an expert on backlight, but his idea sounds simple and an overall improvement to the codebase. I don't think it's fair to block a simple one-line improvement based on the fact that we have an idea (that may or may not be implemented) for a possibly better implementation. Why not apply his patch (in case we conclude it doesn't have any bugs), and then go for the 0-100 idea once someone actually decides to implement it? Besides, isn't there the possibility of having a panel that has a 0-9999 range where the change from 0 to 9990 is negligible, and only 9991-9999 matters, so when we scale to 0-100 it will become basically a on/off switch? We all learned to never underestimate panel hardware. > > BR, > Jani. > > > > >> >> Signed-off-by: Shih-Yuan Lee (FourDollars) <sylee@xxxxxxxxxxxxx> >> --- >> 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 a24df35..697fd4d 100644 >> --- a/drivers/gpu/drm/i915/intel_panel.c >> +++ b/drivers/gpu/drm/i915/intel_panel.c >> @@ -1211,7 +1211,7 @@ 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 = panel->backlight.max - panel->backlight.min; >> props.brightness = scale_hw_to_user(connector, >> panel->backlight.level, >> props.max_brightness); > > -- > Jani Nikula, Intel Open Source Technology Center > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@xxxxxxxxxxxxxxxxxxxxx > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Paulo Zanoni _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/intel-gfx