drm/nouveau/disp: fix DP disable race
[ Upstream commit
e04cfdc9b7398c60dbc70212415ea63b6c6a93ae ]
If a HPD pulse signalling the need to retrain the link occurs between
the KMS driver releasing the output and the supervisor interrupt that
finishes the teardown, it was possible get a NULL-ptr deref.
Avoid this by marking the link as inactive earlier.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>