Commit 9682ac93 authored Feb 07, 2019 by Govinda Rajulu Chenna Committed by Gerrit - the friendly Code Review server May 08, 2019

drm/dp: cache edid for mst physical output ports



The current implementation is caching the edid during add_port
only for logical output ports and depending on get_edid api
to read edid for physical output ports. get_edid for physical
ports is executed only when get_connector ioctl is performed
by drm client.

The get_connector ioctl is locking the operation using mode_config
lock/unlock and get_edid for mst port may take couple of seconds
due to mst sideband operations. This lock/unlock is not allowing
atomic_commit ioctl for other active displays which results in
screen freeze.

This change caches the edid for mst physical ports during the
add_port operation to avoid executing get_edid as part of get_connector
ioctl to complete the ioctl operation as quick as possible. This
unblocks atomic_commit ioctl for other active displays to minimize
the screen freeze issue.

Change-Id: I993d89b8bd84f776494d72bc8ceb48eb62d2322b
Signed-off-by: Govinda Rajulu Chenna <gchenna@codeaurora.org>

parent 54f3590a

drivers/gpu/drm/drm_dp_mst_topology.c

+9 −3

Original line number	Diff line number	Diff line
		@@ -1208,9 +1208,8 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
		drm_dp_put_port(port);
		goto out;
		}
		if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV \|\|
		port->pdt == DP_PEER_DEVICE_SST_SINK) &&
		port->port_num >= DP_MST_LOGICAL_PORT_0) {
		if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV \|\|
		port->pdt == DP_PEER_DEVICE_SST_SINK) {
		port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
		drm_connector_set_tile_property(port->connector);
		}
		@@ -1248,6 +1247,13 @@ static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
		}
		}
		if (old_pdt != port->pdt && !port->input) {
		if ((old_pdt == DP_PEER_DEVICE_DP_LEGACY_CONV \|\|
		old_pdt == DP_PEER_DEVICE_SST_SINK) &&
		port->port_num < DP_MST_LOGICAL_PORT_0) {
		kfree(port->cached_edid);
		port->cached_edid = NULL;
		}

		drm_dp_port_teardown_pdt(port, old_pdt);

		if (drm_dp_port_setup_pdt(port))