drm/dp_mst: Zero assigned PBN when releasing VCPI slots

Zero Port's PBN together with VCPI slots when releasing
allocated VCPI slots. That way when disabling the connector
it will not cause issues in drm_dp_mst_atomic_check verifying
branch bw limit.

Signed-off-by: Mikita Lipski <mikita.lipski@amd.com>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Fixes: cd82d82cbc04 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
Cc: <stable@vger.kernel.org> # v5.6+
Link: https://patchwork.freedesktop.org/patch/msgid/20200407160717.27976-1-mikita.lipski@amd.com

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 70c4b7afed12494951da8fdaa0132733e87ad8bf..283615e448386606183f75983b14a49ca3cc86ae 100644 (file)
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4295,6 +4295,7 @@ int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
        if (pos->vcpi) {
                drm_dp_mst_put_port_malloc(port);
                pos->vcpi = 0;
+               pos->pbn = 0;
        }
 
        return 0;