[PATCH v4 3/3] drm_dp_cec: add MST support
Sam McNally
sammc at chromium.org
Tue May 18 12:35:30 UTC 2021
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 at xs4all.nl>
Signed-off-by: Sam McNally <sammc at chromium.org>
---
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in case the edid is no longer valid at that point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 | 20 ++++++++++++++++----
drivers/gpu/drm/drm_dp_mst_topology.c | 24 ++++++++++++++++++++++++
2 files changed, 40 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_cec.c b/drivers/gpu/drm/drm_dp_cec.c
index 3ab2609f9ec7..1abd3f4654dc 100644
--- a/drivers/gpu/drm/drm_dp_cec.c
+++ b/drivers/gpu/drm/drm_dp_cec.c
@@ -14,6 +14,7 @@
#include <drm/drm_connector.h>
#include <drm/drm_device.h>
#include <drm/drm_dp_helper.h>
+#include <drm/drm_dp_mst_helper.h>
/*
* Unfortunately it turns out that we have a chicken-and-egg situation
@@ -245,13 +246,22 @@ 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 +317,7 @@ 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
@@ -375,6 +385,7 @@ void drm_dp_cec_set_edid(struct drm_dp_aux *aux, const struct edid *edid)
unlock:
mutex_unlock(&aux->cec.lock);
}
+
EXPORT_SYMBOL(drm_dp_cec_set_edid);
/*
@@ -383,7 +394,7 @@ 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);
@@ -393,6 +404,7 @@ void drm_dp_cec_unset_edid(struct drm_dp_aux *aux)
goto unlock;
cec_phys_addr_invalidate(aux->cec.adap);
+
/*
* We're done if we want to keep the CEC device
* (drm_dp_cec_unregister_delay is >= NEVER_UNREG_DELAY) or if the
@@ -428,7 +440,7 @@ 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_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 29aad3b6b31a..5612caf9fb49 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2359,6 +2359,8 @@ 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);
@@ -2382,6 +2384,8 @@ 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);
@@ -2682,6 +2686,21 @@ 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)
{
@@ -4170,6 +4189,8 @@ 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);
@@ -4362,6 +4383,8 @@ 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;
}
@@ -4392,6 +4415,7 @@ 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;
}
--
2.31.1.751.gd2f1c929bd-goog
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