[SRU] [H/Unstable/OEM-5.10] [PATCH 0/1] Fix kernel panic at boot on dual GFX systems

[Kai-Heng Feng]

BugLink: https://bugs.launchpad.net/bugs/1926792

[Impact]
On dual GFX systems, if amdgpu fails to probe a device, vgaarb for
another GFX triggers a NULL pointer dereference and freeze the system.

[Fix]
Defer VGA client registering so resources are handled properly when
amdgpu probe fails.

[Test]
With the patch applied, no more kernel panic when vgaarb is changing the
VGA mode.

[Where problems could occur]
VGA clients won't take effect until a successful probe, so unless there
is very subtle bug in vgaarb or vgaswitcheroo, it's very unlikely to
introduce any regression.

Kai-Heng Feng (1):
  drm/amdgpu: Register VGA clients after init can no longer fail

 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 36 ++++++++++------------
 1 file changed, 17 insertions(+), 19 deletions(-)

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2.30.2