Bug 203427
| Summary: | [REG 4.20 -> 5.0] AMD brightness minimum level is too high | ||
|---|---|---|---|
| Product: | ACPI | Reporter: | Błażej Szczygieł (mumei6102) |
| Component: | Power-Video | Assignee: | acpi_power-video |
| Status: | RESOLVED DUPLICATE | ||
| Severity: | normal | ||
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 5.0 | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
Moved here: https://bugzilla.kernel.org/show_bug.cgi?id=203439 It should be better section to report the amdgpu issue. *** This bug has been marked as a duplicate of bug 203439 *** |
I have Huawei Matebook D 14 with AMD Ryzen 2500U. Since kernel 5.0.x the minimum brightness level is too high. It is not possible to dim the display as much as on previous kernel version. Kernel 4.20 also allows to disable the backlight on level 0. Value of "0" in "/sys/class/backlight/amdgpu_bl0/brightness" currently doesn't disable backlight as in previous version. Value of "1" means the screen is dim, but not as much as in kernel 4.20. Sometimes the screen is still too bright even on level 0 in kernel 5.0. Since commit 206bbafe00dcacccf40e6f09e624329ec124201b I can see the define: > #define AMDGPU_DM_DEFAULT_MIN_BACKLIGHT 12 Maybe it should be defined to "0" to restore the old behavior? (I haven't tested yet)