This is a note to let you know that I've just added the patch titled drm/dp/mst: fixup handling hotplug on port removal. to the 4.2-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-dp-mst-fixup-handling-hotplug-on-port-removal.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From df4839fdc9b3c922586b945f062f38cbbda022bb Mon Sep 17 00:00:00 2001 From: Dave Airlie <airlied@xxxxxxxxxx> Date: Wed, 16 Sep 2015 10:37:28 +1000 Subject: drm/dp/mst: fixup handling hotplug on port removal. From: Dave Airlie <airlied@xxxxxxxxxx> commit df4839fdc9b3c922586b945f062f38cbbda022bb upstream. output ports should always have a connector, unless in the rare case connector allocation fails in the driver. In this case we only need to teardown the pdt, and free the struct, and there is no need to send a hotplug msg. In the case were we add the port to the destroy list we need to send a hotplug if we destroy any connectors, so userspace knows to reprobe stuff. this patch also handles port->connector allocation failing which should be a rare event, but makes the code consistent. Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx> Signed-off-by: Dave Airlie <airlied@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/drm_dp_mst_topology.c | 36 ++++++++++++++++++++++++---------- 1 file changed, 26 insertions(+), 10 deletions(-) --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -863,29 +863,33 @@ static void drm_dp_destroy_port(struct k { struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref); struct drm_dp_mst_topology_mgr *mgr = port->mgr; + if (!port->input) { port->vcpi.num_slots = 0; kfree(port->cached_edid); - /* we can't destroy the connector here, as - we might be holding the mode_config.mutex - from an EDID retrieval */ + /* + * The only time we don't have a connector + * on an output port is if the connector init + * fails. + */ if (port->connector) { + /* we can't destroy the connector here, as + * we might be holding the mode_config.mutex + * from an EDID retrieval */ + mutex_lock(&mgr->destroy_connector_lock); list_add(&port->next, &mgr->destroy_connector_list); mutex_unlock(&mgr->destroy_connector_lock); schedule_work(&mgr->destroy_connector_work); return; } + /* no need to clean up vcpi + * as if we have no connector we never setup a vcpi */ drm_dp_port_teardown_pdt(port, port->pdt); - - if (!port->input && port->vcpi.vcpi > 0) - drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); } kfree(port); - - (*mgr->cbs->hotplug)(mgr); } static void drm_dp_put_port(struct drm_dp_mst_port *port) @@ -1115,12 +1119,21 @@ static void drm_dp_add_port(struct drm_d char proppath[255]; build_mst_prop_path(port, mstb, proppath, sizeof(proppath)); port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath); - + if (!port->connector) { + /* remove it from the port list */ + mutex_lock(&mstb->mgr->lock); + list_del(&port->next); + mutex_unlock(&mstb->mgr->lock); + /* drop port list reference */ + drm_dp_put_port(port); + goto out; + } if (port->port_num >= 8) { port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc); } } +out: /* put reference to this port */ drm_dp_put_port(port); } @@ -2661,7 +2674,7 @@ static void drm_dp_destroy_connector_wor { struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work); struct drm_dp_mst_port *port; - + bool send_hotplug = false; /* * Not a regular list traverse as we have to drop the destroy * connector lock before destroying the connector, to avoid AB->BA @@ -2684,7 +2697,10 @@ static void drm_dp_destroy_connector_wor if (!port->input && port->vcpi.vcpi > 0) drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi); kfree(port); + send_hotplug = true; } + if (send_hotplug) + (*mgr->cbs->hotplug)(mgr); } /** Patches currently in stable-queue which might be from airlied@xxxxxxxxxx are queue-4.2/drm-qxl-only-report-first-monitor-as-connected-if-we-have-no-state.patch queue-4.2/drm-qxl-recreate-the-primary-surface-when-the-bo-is-not-primary.patch queue-4.2/drm-dp-mst-fixup-handling-hotplug-on-port-removal.patch queue-4.2/drm-dp-mst-drop-cancel-work-sync-in-the-mstb-destroy-path-v2.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html