[PATCH 5.6 119/167] drm/dp_mst: Zero assigned PBN when releasing VCPI slots

[Greg Kroah-Hartman]

From: Mikita Lipski <mikita.lipski@xxxxxxx>

commit 7bfc1fec1af3e2f0194843855b0d49054fa42fd2 upstream.

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@xxxxxxx>
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
Fixes: cd82d82cbc04 ("drm/dp_mst: Add branch bandwidth validation to MST atomic check")
Cc: <stable@xxxxxxxxxxxxxxx> # v5.6+
Link: https://patchwork.freedesktop.org/patch/msgid/20200407160717.27976-1-mikita.lipski@xxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/gpu/drm/drm_dp_mst_topology.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -4290,6 +4290,7 @@ int drm_dp_atomic_release_vcpi_slots(str
 	if (pos->vcpi) {
 		drm_dp_mst_put_port_malloc(port);
 		pos->vcpi = 0;
+		pos->pbn = 0;
 	}
 
 	return 0;