4.13-stable review patch. If anyone has any objections, please let me know.
------------------
From: Ben Skeggs <bskeggs@xxxxxxxxxx>
commit 227f66d2f9954f68375736af62ebcd73c6754d69 upstream.
Reported-by: Woody Suwalski <terraluna977@xxxxxxxxx>
Signed-off-by: Ben Skeggs <bskeggs@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/nouveau/nv50_display.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -3281,11 +3281,14 @@ nv50_mstm = {
void
nv50_mstm_service(struct nv50_mstm *mstm)
{
- struct drm_dp_aux *aux = mstm->mgr.aux;
+ struct drm_dp_aux *aux = mstm ? mstm->mgr.aux : NULL;
bool handled = true;
int ret;
u8 esi[8] = {};
+ if (!aux)
+ return;
+
while (handled) {
ret = drm_dp_dpcd_read(aux, DP_SINK_COUNT_ESI, esi, 8);
if (ret != 8) {