Messages in this thread | | | From | Robert Jarzmik <> | Subject | Re: [PATCH] backlight: pwm_bl: Fix brightness levels for non-DT case. | Date | Sat, 25 Aug 2018 10:04:10 +0200 |
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Enric Balletbo i Serra <enric.balletbo@collabora.com> writes:
> Commit '88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED > linearly to human eye")' allows the possibility to compute a default > brightness table when there isn't the brightness-levels property in the > DT. Unfortunately the changes made broke the pwm backlight for the > non-DT boards. > > Usually, the non-DT boards don't pass the brightness levels via platform > data, instead, they set the max_brightness in their platform data and the > driver calculates the level without a table. The ofending patch assumed > that when there is no brightness levels table we should create one, but this > is clearly wrong for the non-DT case. > > After this patch the code handles the DT and the non-DT case taking in > consideration also if max_brightness is set or not. The default table is > only created when neither, brightness-levels and max_brightness, are > set. > > The patch also fixes another issue found by Robert. Before this patch > looks like a division by 0 was possible when state.period returned 0 by > pwm_get_state(). This is because pwm_get_state() was called before > pwm_apply_args() so state.period was not initialized. The patch moves > the pwm_apply_args() call before any call to pwm_get_state(). > > Fixes: '88ba95bedb79 ("backlight: pwm_bl: Compute brightness of LED linearly to human eye")' > Reported-by: Robert Jarzmik <robert.jarzmik@free.fr> > Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Tested-by: Robert Jarzmik <robert.jarzmik@free.fr>
Cheers.
-- Robert
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