diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 2e2af13f70d5..d3fc7e4e85b7 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2479,20 +2479,17 @@ int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
 
 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
-			    struct drm_dp_vcpi *vcpi, int pbn)
+			    struct drm_dp_vcpi *vcpi, int pbn, int slots)
 {
-	int num_slots;
 	int ret;
 
-	num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
-
 	/* max. time slots - one slot for MTP header */
-	if (num_slots > 63)
+	if (slots > 63)
 		return -ENOSPC;
 
 	vcpi->pbn = pbn;
-	vcpi->aligned_pbn = num_slots * mgr->pbn_div;
-	vcpi->num_slots = num_slots;
+	vcpi->aligned_pbn = slots * mgr->pbn_div;
+	vcpi->num_slots = slots;
 
 	ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
 	if (ret < 0)
@@ -2507,7 +2504,8 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
  * @pbn: payload bandwidth number to request
  * @slots: returned number of slots for this PBN.
  */
-bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
+bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
+			      struct drm_dp_mst_port *port, int pbn, int slots)
 {
 	int ret;
 
@@ -2515,16 +2513,18 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp
 	if (!port)
 		return false;
 
+	if (slots < 0)
+		return false;
+
 	if (port->vcpi.vcpi > 0) {
 		DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
 		if (pbn == port->vcpi.pbn) {
-			*slots = port->vcpi.num_slots;
 			drm_dp_put_port(port);
 			return true;
 		}
 	}
 
-	ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
+	ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
 	if (ret) {
 		DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
 				DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
@@ -2532,7 +2532,6 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp
 	}
 	DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
 			pbn, port->vcpi.num_slots);
-	*slots = port->vcpi.num_slots;
 
 	drm_dp_put_port(port);
 	return true;
diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
index 38e3ca2f6f18..f51574f7f160 100644
--- a/drivers/gpu/drm/i915/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/intel_dp_mst.c
@@ -147,7 +147,6 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
 		to_intel_connector(conn_state->connector);
 	int ret;
 	uint32_t temp;
-	int slots;
 
 	/* MST encoders are bound to a crtc, not to a connector,
 	 * force the mapping here for get_hw_state.
@@ -177,7 +176,8 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
 
 	ret = drm_dp_mst_allocate_vcpi(&intel_dp->mst_mgr,
 				       connector->port,
-				       pipe_config->pbn, &slots);
+				       pipe_config->pbn,
+				       pipe_config->dp_m_n.tu);
 	if (ret == false) {
 		DRM_ERROR("failed to allocate vcpi\n");
 		return;
diff --git a/drivers/gpu/drm/nouveau/nv50_display.c b/drivers/gpu/drm/nouveau/nv50_display.c
index 16915c29ec52..a58c53639c18 100644
--- a/drivers/gpu/drm/nouveau/nv50_display.c
+++ b/drivers/gpu/drm/nouveau/nv50_display.c
@@ -2895,7 +2895,8 @@ nv50_msto_enable(struct drm_encoder *encoder)
 	if (WARN_ON(!mstc))
 		return;
 
-	r = drm_dp_mst_allocate_vcpi(&mstm->mgr, mstc->port, mstc->pbn, &slots);
+	slots = drm_dp_find_vcpi_slots(&mstm->mgr, mstc->pbn);
+	r = drm_dp_mst_allocate_vcpi(&mstm->mgr, mstc->port, mstc->pbn, slots);
 	WARN_ON(!r);
 
 	if (mstm->outp->dcb->sorconf.link & 1)
diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c b/drivers/gpu/drm/radeon/radeon_dp_mst.c
index 7d5ada3980dc..6598306dca9b 100644
--- a/drivers/gpu/drm/radeon/radeon_dp_mst.c
+++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c
@@ -453,9 +453,11 @@ radeon_mst_encoder_dpms(struct drm_encoder *encoder, int mode)
 		DRM_DEBUG_KMS("dig encoder is %d %d %d\n", dig_enc->dig_encoder,
 			      dig_enc->linkb, radeon_crtc->crtc_id);
 
+		slots = drm_dp_find_vcpi_slots(&radeon_connector->mst_port->mst_mgr,
+					       mst_enc->pbn);
 		ret = drm_dp_mst_allocate_vcpi(&radeon_connector->mst_port->mst_mgr,
 					       radeon_connector->port,
-					       mst_enc->pbn, &slots);
+					       mst_enc->pbn, slots);
 		ret = drm_dp_update_payload_part1(&radeon_connector->mst_port->mst_mgr);
 
 		radeon_dp_mst_set_be_cntl(primary, mst_enc,
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index d8365110eb23..5b024764666c 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -567,7 +567,8 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_
 int drm_dp_calc_pbn_mode(int clock, int bpp);
 
 
-bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots);
+bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
+			      struct drm_dp_mst_port *port, int pbn, int slots);
 
 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port);