Hi Guillaume, > Il 22/10/2021 14:34 Guillaume GARDET <guillaume.gar...@free.fr> ha scritto: > > > Hi Dario, > > ----- Dario Binacchi <dario...@libero.it> a écrit : > > Hi Guillaume, > > > > > Il 21/10/2021 16:47 Guillaume GARDET <guillaume.gar...@free.fr> ha > > > scritto: > > > > > > > > > Hi, > > > > > > Commit 76c2ff3e [0] broke backlight on Chromebook snow. > > > A revert on top of 2021.10 restores the backlight. > > > Not sure why it breaks on Chromebook snow yet. Dario, any idea how to fix > > > this? > > > > Is it possible that max_level is equal to min_level and therefore division > > by zero is done? > > I do not think so, because u-boot does not crash and the DTS file has > multiple levels: > https://source.denx.de/u-boot/u-boot/-/blob/master/arch/arm/dts/exynos5250-snow.dts#L243 > > I think the problem occurs when 'cur_level == max_level', which is also the > default value in the DTS. > If I change the default-brightness-level to 6 (instead of 7), then the > backlight works again, which would confirm the assumption above.
I have set the default-brightness-level to max-level on my beaglebone board but the backlight works the same. I didn't see any difference. Thanks and regards Dario > pwm_backlight_set_brightness seems to set cur_level to max value by default. > Maybe the driver thinks there is nothing to do, since current level is also > the desired level? > > > Cheers, > Guillaume > > > > > > Thanks and regards, > > Dario > > > > > > Cheers, > > > Guillaume
