With DP v2.0 errata E5, CEC tunneling can be supported through an MST topology.
When tunneling CEC through an MST port, CEC IRQs are delivered via a sink event notify message; when a sink event notify message is received, trigger CEC IRQ handling - ESI1 is not used for remote CEC IRQs so its value is not checked.
Register and unregister for all MST connectors, ensuring their drm_dp_aux_cec struct won't be accessed uninitialized.
Reviewed-by: Hans Verkuil hverkuil-cisco@xs4all.nl Reviewed-by: Lyude Paul lyude@redhat.com Reported-by: kernel test robot lkp@intel.com Signed-off-by: Sam McNally sammc@chromium.org ---
Changes in v7: - Added mutex_init() for aux->cec.lock
Changes in v6: - Removed superfluous #include <drm/drm_dp_mst_helper.h> - Removed spurious added newlines
Changes in v4: - Removed use of work queues - Updated checks of aux.transfer to accept aux.is_remote
Changes in v3: - Fixed whitespace in drm_dp_cec_mst_irq_work() - Moved drm_dp_cec_mst_set_edid_work() with the other set_edid functions
Changes in v2: - Used aux->is_remote instead of aux->cec.is_mst, removing the need for the previous patch in the series - Added a defensive check for null edid in the deferred set_edid work, in case the edid is no longer valid at that point
drivers/gpu/drm/drm_dp_cec.c | 17 +++++++++++++---- drivers/gpu/drm/drm_dp_helper.c | 3 ++- drivers/gpu/drm/drm_dp_mst_topology.c | 24 ++++++++++++++++++++++++ 3 files changed, 39 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_cec.c b/drivers/gpu/drm/drm_dp_cec.c index 3ab2609f9ec7..61c59e2c4b3e 100644 --- a/drivers/gpu/drm/drm_dp_cec.c +++ b/drivers/gpu/drm/drm_dp_cec.c @@ -245,13 +245,22 @@ void drm_dp_cec_irq(struct drm_dp_aux *aux) int ret;
/* No transfer function was set, so not a DP connector */ - if (!aux->transfer) + if (!aux->transfer && !aux->is_remote) return;
mutex_lock(&aux->cec.lock); if (!aux->cec.adap) goto unlock;
+ if (aux->is_remote) { + /* + * For remote connectors, CEC IRQ is triggered by an explicit + * message so ESI1 is not involved. + */ + drm_dp_cec_handle_irq(aux); + goto unlock; + } + ret = drm_dp_dpcd_readb(aux, DP_DEVICE_SERVICE_IRQ_VECTOR_ESI1, &cec_irq); if (ret < 0 || !(cec_irq & DP_CEC_IRQ)) @@ -307,7 +316,7 @@ void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid) u8 cap;
/* No transfer function was set, so not a DP connector */ - if (!aux->transfer) + if (!aux->transfer && !aux->is_remote) return;
#ifndef CONFIG_MEDIA_CEC_RC @@ -383,7 +392,7 @@ EXPORT_SYMBOL(drm_dp_cec_set_edid); void drm_dp_cec_unset_edid(struct drm_dp_aux *aux) { /* No transfer function was set, so not a DP connector */ - if (!aux->transfer) + if (!aux->transfer && !aux->is_remote) return;
cancel_delayed_work_sync(&aux->cec.unregister_work); @@ -428,7 +437,7 @@ void drm_dp_cec_register_connector(struct drm_dp_aux *aux, struct drm_connector *connector) { WARN_ON(aux->cec.adap); - if (WARN_ON(!aux->transfer)) + if (WARN_ON(!aux->transfer && !aux->is_remote)) return; aux->cec.connector = connector; INIT_DELAYED_WORK(&aux->cec.unregister_work, diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 24bbc710c825..db566062058c 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1723,10 +1723,11 @@ static void drm_dp_aux_crc_work(struct work_struct *work) * @aux: DisplayPort AUX channel * * Used for remote aux channel in general. Merely initialize the crc work - * struct. + * struct and CEC lock. */ void drm_dp_remote_aux_init(struct drm_dp_aux *aux) { + mutex_init(&aux->cec.lock); INIT_WORK(&aux->crc_work, drm_dp_aux_crc_work); } EXPORT_SYMBOL(drm_dp_remote_aux_init); diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 1cc1a58cfa8b..b58c884fe67b 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2362,6 +2362,8 @@ static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, int drm_dp_mst_connector_late_register(struct drm_connector *connector, struct drm_dp_mst_port *port) { + drm_dp_cec_register_connector(&port->aux, connector); + drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n", port->aux.name, connector->kdev->kobj.name);
@@ -2385,6 +2387,8 @@ void drm_dp_mst_connector_early_unregister(struct drm_connector *connector, drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n", port->aux.name, connector->kdev->kobj.name); drm_dp_aux_unregister_devnode(&port->aux); + + drm_dp_cec_unregister_connector(&port->aux); } EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
@@ -2662,6 +2666,21 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, queue_work(system_long_wq, &mstb->mgr->work); }
+static void +drm_dp_mst_handle_sink_event(struct drm_dp_mst_branch *mstb, + struct drm_dp_sink_event_notify *sink_event) +{ + struct drm_dp_mst_port *port; + + if (sink_event->event_id & DP_SINK_EVENT_CEC_IRQ_EVENT) { + port = drm_dp_get_port(mstb, sink_event->port_number); + if (port) { + drm_dp_cec_irq(&port->aux); + drm_dp_mst_topology_put_port(port); + } + } +} + static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, u8 lct, u8 *rad) { @@ -4177,6 +4196,8 @@ drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) { drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); hotplug = true; + } else if (msg->req_type == DP_SINK_EVENT_NOTIFY) { + drm_dp_mst_handle_sink_event(mstb, &msg->u.sink_event); }
drm_dp_mst_topology_put_mstb(mstb); @@ -4369,6 +4390,8 @@ drm_dp_mst_detect_port(struct drm_connector *connector, break; } out: + if (ret != connector_status_connected) + drm_dp_cec_unset_edid(&port->aux); drm_dp_mst_topology_put_port(port); return ret; } @@ -4399,6 +4422,7 @@ struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_ edid = drm_get_edid(connector, &port->aux.ddc); } port->has_audio = drm_detect_monitor_audio(edid); + drm_dp_cec_set_edid(&port->aux, edid); drm_dp_mst_topology_put_port(port); return edid; }