Messages in this thread | | | Subject | Re: Re: [PATCH] backlight: pwm_bl: Fix brightness levels for non-DT case. | From | Daniel Thompson <> | Date | Thu, 20 Sep 2018 09:23:49 -0700 |
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On 25/08/18 01:04, Robert Jarzmik wrote: > 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>
Acked-by: Daniel Thompson <daniel.thompson@linaro.org>
(and sorry for the delay)
Daniel.
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