Le vendredi 27 novembre 2020 à 14:50:06 UTC+1, prog-a...@tutamail.com a écrit : [...] > Hello, the brightness doesn't work (cursor moves but not real brightness). [...] > i915 0000:00:02.0 : [drm] *ERROR* Failed to get the PMIC PWM chip > i915 0000:00:02.0 : [drm] *ERROR* [CRTC:51:pipe A] mismatch in pixel_rate > i915 0000:00:02.0 : [drm] *ERROR* [CRTC:51:pipe A] mismatch in > hw_adjusted_mode.crtc_clock > i915 0000:00:02.0 : [drm] *ERROR* [CRTC:51:pipe A] mismatch in port_clock > > Information about device and version : > My device is an HP Pro Tablet 608 (CPU : Intel Atom X5-Z8500, 64 bits, RAM : > 4GB) > I am using Debian Testing GNU/Linux 5.9 (but this bug appears also in 5.8, > and Stable version), kernel 5.9.0-1-amd64, GNOME 3.38.1 under Wayland. > Possible solution after test with Fedora (GNOME/Wayland/similar kernel) : > Brightness can be controlled fine. It seems that this bug has been already > fixed in Fedora with patches (c.f. : > https://patchwork.freedesktop.org/series/69686/). [...]
Hello, This could be caused by the firmware-misc-nonfree package being not installed. https://wiki.debian.org/Firmware?highlight=%28i915%29 (i915 section) Albeit Fedora/RedHat/Centos are dedicated to free (as in speech) software by default, as is Debian, the formers consider non-free firmwares mandatory for a usable distribution ans thus provide it by default while the latter does not (policy difference). (I am almost certain the above mentioned patch is present in Debian Testing)
