On Mon, Aug 10, 2026 at 07:12:24AM +0100, Jason McIntyre wrote: > > try this revert of 6.18.42's > > drm/amd/display: Fix backlight max_brightness to match exported range > > > > yes, the revert fixes it. > > thanks, > jmc
appears to be the same problem described in https://gitlab.freedesktop.org/drm/amd/-/work_items/5562 Can you drop the previous patch and try the one below? adapted from drm/amd/display: Set default backlight without ACPI support https://lore.kernel.org/amd-gfx/[email protected]/ Index: sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c =================================================================== RCS file: /cvs/src/sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c,v diff -u -p -r1.204 amdgpu_dm.c --- sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c 10 Aug 2026 06:28:36 -0000 1.204 +++ sys/dev/pci/drm/amd/display/amdgpu_dm/amdgpu_dm.c 10 Aug 2026 12:49:15 -0000 @@ -4933,20 +4933,16 @@ static void amdgpu_dm_update_backlight_c caps->caps_valid = false; } } - +#else + if (caps->aux_support) + return; +#endif if (!caps->caps_valid) { caps->min_input_signal = AMDGPU_DM_DEFAULT_MIN_BACKLIGHT; caps->max_input_signal = AMDGPU_DM_DEFAULT_MAX_BACKLIGHT; + caps->ac_level = caps->dc_level = 50; caps->caps_valid = true; } -#else - if (caps->aux_support) - return; - - caps->min_input_signal = AMDGPU_DM_DEFAULT_MIN_BACKLIGHT; - caps->max_input_signal = AMDGPU_DM_DEFAULT_MAX_BACKLIGHT; - caps->caps_valid = true; -#endif } static int get_brightness_range(const struct amdgpu_dm_backlight_caps *caps,
