External thunderbolt3 & built-in monitor black out on AMD Ryzen 9 PRO 7940HS w/ Radeon 780M Graphics
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
HWE Next |
New
|
Undecided
|
Unassigned | ||
OEM Priority Project |
Fix Released
|
Critical
|
Andy Chi | ||
linux-firmware (Ubuntu) |
Fix Released
|
High
|
You-Sheng Yang | ||
Jammy |
Fix Released
|
High
|
You-Sheng Yang | ||
Lunar |
Fix Released
|
High
|
You-Sheng Yang | ||
Mantic |
Fix Released
|
High
|
You-Sheng Yang |
Bug Description
[SRU Justification]
[Impact]
Monitors black out when an external one connects via thunderbolt3 on AMD Ryzen
9 PRO 7940HS w/ Radeon 780M Graphics.
[Fix]
This can be fixed by upstream linux-firmware commit 253cc179d849 ("amdgpu:
Update DMCUB for DCN314 & Yellow Carp").
However, in linux-firmware/
files to be updated often associated with many other more, they're now updated
with overwrites without cherry-pick ancestor commits along the history.
For linux-firmware/
[Test Case]
Connect an tbt3 featured external monitor (ASUS PA27AC) after boot to GUI.
Check if both the built-in and external monitors lights up as usual.
[Where problems could occur]
Update amdgpu firmware are error prone, verified on targeting series as
possible.
[Other Info]
While this affects linux-oem-
and Lunar are nominated for fix.
========== original bug report ==========
When connect the tbt3 external monitor, both the build-in and the external monitor show black.
This can be fixed by https:/
tags: | added: kern-7609 |
tags: | added: verification-done-jammy verification-done-lunar |
tags: | added: originate-from-2026326 |
Changed in oem-priority: | |
status: | New → Fix Released |
importance: | Undecided → Critical |
assignee: | nobody → Andy Chi (andch) |
While this affects linux-oem-6.1/jammy kernel, linux-firmware/ jammy will be nominated for fix.