Bug 213715
| Summary: | failed to change brightness of HDR panel on AMD GREEN_SARDINE through aux | ||
|---|---|---|---|
| Product: | Drivers | Reporter: | Pengyu Ma (mapengyu) |
| Component: | Video(DRI - non Intel) | Assignee: | drivers_video-dri |
| Status: | NEW --- | ||
| Severity: | blocking | CC: | alexdeucher, mario.limonciello |
| Priority: | P1 | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Kernel Version: | 5.14.0-rc1+ | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
dmesg
4k display edid |
||
Created attachment 297821 [details]
4k display edid
I would suggest to work with BOE and CSO to fix the DPCD values in panel firmware to not report aux control if it is not functional. You can see the kernel checks the DPCD to determine whether to use AUX or PWM. https://github.com/torvalds/linux/blob/c010efb7f0bc0c3cb2cd26b000f71d4bd0c427cd/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c#L2433 BTW this behavior has been also been reported in the past, so a heuristic may be introduced at some point in the future for the buggy panel firmware: https://gitlab.freedesktop.org/drm/amd/-/issues/1438 |
Created attachment 297819 [details] dmesg HW: ThinkPad P14s gen 2a CPU: AMD Ryzen 7 PRO 5850U with Radeon Graphics Panel: BOE 2434 and CSO 5127 brightness can't be controlled through AUX. It works with parameter "amdgpu.backlight=0" dmesg attached.