[PATCH v2 15/16] drm/dp_mst: Check payload count in drm_dp_mst_atomic_check()

[Lyude Paul]

It occurred to me that we never actually check this! So let's start
doing that.

Signed-off-by: Lyude Paul <lyude at redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: David Airlie <airlied at redhat.com>
Cc: Jerry Zuo <Jerry.Zuo at amd.com>
Cc: Harry Wentland <harry.wentland at amd.com>
Cc: Juston Li <juston.li at intel.com>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index b55b58bf86ba..455fcf0a82df 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3061,8 +3061,6 @@ int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
 	if (port == NULL)
 		return -EINVAL;
 
-	topology_state->vcpi_allocated = true;
-
 	/* Find the current allocation for this port, if any */
 	list_for_each_entry(pos, &topology_state->vcpis, next) {
 		if (pos->port == port) {
@@ -3599,7 +3597,6 @@ drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
 	__drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
 
 	INIT_LIST_HEAD(&state->vcpis);
-	state->vcpi_allocated = false;
 
 	list_for_each_entry(pos, &old_state->vcpis, next) {
 		/* Prune leftover freed VCPI allocations */
@@ -3648,7 +3645,7 @@ drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
 				       struct drm_dp_mst_topology_state *mst_state)
 {
 	struct drm_dp_vcpi_allocation *vcpi;
-	int avail_slots = 63;
+	int avail_slots = 63, payload_count = 0;
 
 	list_for_each_entry(vcpi, &mst_state->vcpis, next) {
 		/* Releasing VCPI is always OK-even if the port is gone */
@@ -3669,6 +3666,12 @@ drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
 			return -ENOSPC;
 		}
 
+		if (++payload_count > mgr->max_payloads) {
+			DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
+					 mgr, mst_state, mgr->max_payloads);
+			return -EINVAL;
+		}
+
 	}
 	DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
 			 mgr, mst_state, avail_slots,
-- 
2.19.2