drm: use mgr->dev in drm_dbg_kms in drm_dp_add_payload_part2

I've been experiencing some intermittent crashes down in the display
driver code. The symptoms are ususally a line like this in dmesg:

    amdgpu 0000:30:00.0: [drm] Failed to create MST payload for port 000000006d3a3885: -5

...followed by an Oops due to a NULL pointer dereference.

Switch to using mgr->dev instead of state->dev since "state" can be
NULL in some cases.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=2184855
Suggested-by: Jani Nikula <jani.nikula@linux.intel.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230419112447.18471-1-jlayton@kernel.org

diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 38dab76..e2e21ce 100644 (file)
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -3404,7 +3404,7 @@ int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr,
 
        /* Skip failed payloads */
        if (payload->vc_start_slot == -1) {
-               drm_dbg_kms(state->dev, "Part 1 of payload creation for %s failed, skipping part 2\n",
+               drm_dbg_kms(mgr->dev, "Part 1 of payload creation for %s failed, skipping part 2\n",
                            payload->port->connector->name);
                return -EIO;
        }