linux-kernel - [PATCH 4.4 074/146] drm/dp/mst: Always clear proposed vcpi table for port.

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Date:	Mon, 25 Jul 2016 13:55:29 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org,
	Andrey Grodzovsky <Andrey.Grodzovsky@....com>,
	Lyude <cpaul@...hat.com>,
	Mykola Lysenko <Mykola.Lysenko@....com>,
	Alex Deucher <alexander.deucher@....com>
Subject: [PATCH 4.4 074/146] drm/dp/mst: Always clear proposed vcpi table for port.

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andrey Grodzovsky <Andrey.Grodzovsky@....com>

commit fd2d2bac6e79b0be91ab86a6075a0c46ffda658a upstream.

Not clearing mst manager's proposed vcpis table for destroyed connectors when the manager is stopped leaves it pointing to unrefernced memory, this causes pagefault when the manager is restarted when plugging back a branch.

Fixes: 91a25e463130 ("drm/dp/mst: deallocate payload on port destruction")
Signed-off-by: Andrey Grodzovsky <Andrey.Grodzovsky@....com>
Reviewed-by: Lyude <cpaul@...hat.com>
Cc: Mykola Lysenko <Mykola.Lysenko@....com>
Cc: Alex Deucher <alexander.deucher@....com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/gpu/drm/drm_dp_mst_topology.c |    8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2874,11 +2874,9 @@ static void drm_dp_destroy_connector_wor
 		drm_dp_port_teardown_pdt(port, port->pdt);
 
 		if (!port->input && port->vcpi.vcpi > 0) {
-			if (mgr->mst_state) {
-				drm_dp_mst_reset_vcpi_slots(mgr, port);
-				drm_dp_update_payload_part1(mgr);
-				drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
-			}
+			drm_dp_mst_reset_vcpi_slots(mgr, port);
+			drm_dp_update_payload_part1(mgr);
+			drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
 		}
 
 		kref_put(&port->kref, drm_dp_free_mst_port);