[PATCH 0/1][SRU][J/OEM-5.17] Fix AMDGPU: No video output and system hangs with two monitor (dGPU: W6400)

[Tim Gardner]

On 9/15/22 01:50, Koba Ko wrote:
> BugLink: https://bugs.launchpad.net/bugs/1989647
> 
> [Impact]
> There's possibility that system will hang and no video output of two external monitor with dGPU W6400
> 
> Monitor 1: ASUS ProArt PA238Q (FHD)
> Monitor 2: Dell P2415Q (4K)
> 
> [Fix]
> Introduce the dmi quirk in amdgpu,
> and add dmi quirks to bypass the affected machine.
> 
> [Test Case]
> Two ways to verify
> 
> Method 1:
> 1. Cold boot with ASUS
> 2. Attach Dell monitor. ASUS is primary.
> 3. Switch display mode to single ASUS
> 4. Switch disaply mode back to Joing Displays. ASUS is primary
> 
> Method 2:
> 1. Cold boot with two monitors. ASUS is primary
> 2. Unplug the DP cable of Dell monitor from DUT and wait for few seconds
> 3. Plug it back to DUT
> 
> [Where problems could occur]
> Low, add a dmi quirk to bypass the target machine.
> 
> Fangzhi Zuo (1):
>    drm/amd/display: Ignore First MST Sideband Message Return Error
> 
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 39 +++++++++++++++++++
>   .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.h |  8 ++++
>   .../display/amdgpu_dm/amdgpu_dm_mst_types.c   | 17 ++++++++
>   3 files changed, 64 insertions(+)
> 
Already in Jammy stable updates:

linux-5.15.y.txt:c7720f23bb93628f30f16d033eaefbe2540f1b5e 
drm/amd/display: Ignore First MST Sideband Message Return Error
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Tim Gardner
Canonical, Inc