Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[linux.git] / drivers / gpu / drm / drm_dp_mst_topology.c

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 5ff1d79b86c4a532917e819cfed3c4c702a3ea07..0e0df398222d1e0220b4388d0513bf73f66164ae 100644 (file)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1275,6 +1275,9 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_
        mutex_lock(&mgr->lock);
        mstb = mgr->mst_primary;
 
+       if (!mstb)
+               goto out;
+
        for (i = 0; i < lct - 1; i++) {
                int shift = (i % 2) ? 0 : 4;
                int port_num = (rad[i / 2] >> shift) & 0xf;