Re: [PATCH 2/3] backlight: pwm_bl: Artificially add 0% during interpolation
From: <hidden>
Date: 2020-08-07 08:21:21
Also in:
dri-devel, linux-pwm, lkml
On Mon, Jul 20, 2020 at 09:25:21PM -0700, Alexandru Stan wrote:
quoted hunk ↗ jump to hunk
Some displays need the low end of the curve cropped in order to make them happy. In that case we still want to have the 0% point, even though anything between 0% and 5%(example) would be skipped. Signed-off-by: Alexandru Stan <redacted> --- drivers/video/backlight/pwm_bl.c | 8 ++++++++ 1 file changed, 8 insertions(+)diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c index 5193a72305a2..b24711ddf504 100644 --- a/drivers/video/backlight/pwm_bl.c +++ b/drivers/video/backlight/pwm_bl.c@@ -349,6 +349,14 @@ static int pwm_backlight_parse_dt(struct device *dev, /* Fill in the last point, since no line starts here. */ table[x2] = y2; + /* + * If we don't start at 0 yet we're increasing, assume + * the dts wanted to crop the low end of the range, so + * insert a 0 to provide a display off mode. + */ + if (table[0] > 0 && table[0] < table[num_levels - 1]) + table[0] = 0;
Isn't that what the enable/disable switch in backlights are for? There's lots of backligh drivers (mostly the firmware variety) where setting the backlight to 0 does not shut it off, it's just the lowest setting. But I've not been involved in the details of these discussions. -Daniel
+ /* * As we use interpolation lets remove current * brightness levels table and replace for the -- 2.27.0 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch