[PATCH v2 1/1] drm/dp_mst: Handle SST-only branch device case
Wayne Lin
Wayne.Lin at amd.com
Fri Jan 17 06:03:50 UTC 2020
[Why]
While handling LINK_ADDRESS reply, current code expects a peer device
can handle sideband message once the peer device type is reported as
DP_PEER_DEVICE_MST_BRANCHING. However, when the connected device is
a SST branch case, it can't handle the sideband message(MST_CAP=0 in
DPCD 00021h).
Current code will try to send LINK_ADDRESS to SST branch device and end
up with message timeout and monitor can't display normally. As the
result of that, we should take SST branch device into account.
[How]
According to DP 1.4 spec, we can use Peer_Device_Type as
DP_PEER_DEVICE_MST_BRANCHING and Message_Capability_Status as 0 to
indicate peer device as a SST-only branch device.
Fix following:
- Add the function drm_dp_mst_is_dp_mst_end_device() to decide whether a
peer device connected to a DFP is mst end device. Which also indicates
if the peer device is capable of handling message or not.
- Take SST-only branch device case into account in
drm_dp_port_set_pdt() and add a new parameter 'new_mcs'. Take sst branch
device case as the same case as DP_PEER_DEVICE_DP_LEGACY_CONV and
DP_PEER_DEVICE_SST_SINK. All original handling logics remain.
- Take SST-only branch device case into account in
drm_dp_mst_port_add_connector().
- Fix some parts in drm_dp_mst_handle_link_address_port() to have SST
branch device case into consideration.
- Fix the arguments of drm_dp_port_set_pdt() in
drm_dp_mst_handle_conn_stat().
- Have SST branch device also report
connector_status_connected when the ddps is true
in drm_dp_mst_detect_port()
- Fix the arguments of drm_dp_port_set_pdt() in
drm_dp_delayed_destroy_port()
Changes since v1:(https://patchwork.kernel.org/patch/11323079/)
* Squash previous patch into one patch and merge the commit message here.
* Combine the if statements mentioned in comments
Fixes: c485e2c97dae ("drm/dp_mst: Refactor pdt setup/teardown, add more locking")
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
Cc: Harry Wentland <hwentlan at amd.com>
Cc: Lyude Paul <lyude at redhat.com>
Signed-off-by: Wayne Lin <Wayne.Lin at amd.com>
Reviewed-by: Lyude Paul <lyude at redhat.com>
---
drivers/gpu/drm/drm_dp_mst_topology.c | 140 +++++++++++++++-----------
1 file changed, 80 insertions(+), 60 deletions(-)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 79691c553182..c40a9bd63cfb 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -1914,73 +1914,90 @@ static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
return parent_lct + 1;
}
-static int drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt)
+static bool drm_dp_mst_is_dp_mst_end_device(u8 pdt, bool mcs)
+{
+ switch (pdt) {
+ case DP_PEER_DEVICE_DP_LEGACY_CONV:
+ case DP_PEER_DEVICE_SST_SINK:
+ return true;
+ case DP_PEER_DEVICE_MST_BRANCHING:
+ /* For sst branch device */
+ if (!mcs)
+ return true;
+
+ return false;
+ }
+ return true;
+}
+
+static int
+drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
+ bool new_mcs)
{
struct drm_dp_mst_topology_mgr *mgr = port->mgr;
struct drm_dp_mst_branch *mstb;
u8 rad[8], lct;
int ret = 0;
- if (port->pdt == new_pdt)
+ if (port->pdt == new_pdt && port->mcs == new_mcs)
return 0;
/* Teardown the old pdt, if there is one */
- switch (port->pdt) {
- case DP_PEER_DEVICE_DP_LEGACY_CONV:
- case DP_PEER_DEVICE_SST_SINK:
- /*
- * If the new PDT would also have an i2c bus, don't bother
- * with reregistering it
- */
- if (new_pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
- new_pdt == DP_PEER_DEVICE_SST_SINK) {
- port->pdt = new_pdt;
- return 0;
- }
+ if (port->pdt != DP_PEER_DEVICE_NONE) {
+ if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
+ /*
+ * If the new PDT would also have an i2c bus,
+ * don't bother with reregistering it
+ */
+ if (new_pdt != DP_PEER_DEVICE_NONE &&
+ drm_dp_mst_is_dp_mst_end_device(new_pdt, new_mcs)) {
+ port->pdt = new_pdt;
+ port->mcs = new_mcs;
+ return 0;
+ }
- /* remove i2c over sideband */
- drm_dp_mst_unregister_i2c_bus(&port->aux);
- break;
- case DP_PEER_DEVICE_MST_BRANCHING:
- mutex_lock(&mgr->lock);
- drm_dp_mst_topology_put_mstb(port->mstb);
- port->mstb = NULL;
- mutex_unlock(&mgr->lock);
- break;
+ /* remove i2c over sideband */
+ drm_dp_mst_unregister_i2c_bus(&port->aux);
+ } else {
+ mutex_lock(&mgr->lock);
+ drm_dp_mst_topology_put_mstb(port->mstb);
+ port->mstb = NULL;
+ mutex_unlock(&mgr->lock);
+ }
}
port->pdt = new_pdt;
- switch (port->pdt) {
- case DP_PEER_DEVICE_DP_LEGACY_CONV:
- case DP_PEER_DEVICE_SST_SINK:
- /* add i2c over sideband */
- ret = drm_dp_mst_register_i2c_bus(&port->aux);
- break;
+ port->mcs = new_mcs;
- case DP_PEER_DEVICE_MST_BRANCHING:
- lct = drm_dp_calculate_rad(port, rad);
- mstb = drm_dp_add_mst_branch_device(lct, rad);
- if (!mstb) {
- ret = -ENOMEM;
- DRM_ERROR("Failed to create MSTB for port %p", port);
- goto out;
- }
+ if (port->pdt != DP_PEER_DEVICE_NONE) {
+ if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
+ /* add i2c over sideband */
+ ret = drm_dp_mst_register_i2c_bus(&port->aux);
+ } else {
+ lct = drm_dp_calculate_rad(port, rad);
+ mstb = drm_dp_add_mst_branch_device(lct, rad);
+ if (!mstb) {
+ ret = -ENOMEM;
+ DRM_ERROR("Failed to create MSTB for port %p",
+ port);
+ goto out;
+ }
- mutex_lock(&mgr->lock);
- port->mstb = mstb;
- mstb->mgr = port->mgr;
- mstb->port_parent = port;
+ mutex_lock(&mgr->lock);
+ port->mstb = mstb;
+ mstb->mgr = port->mgr;
+ mstb->port_parent = port;
- /*
- * Make sure this port's memory allocation stays
- * around until its child MSTB releases it
- */
- drm_dp_mst_get_port_malloc(port);
- mutex_unlock(&mgr->lock);
+ /*
+ * Make sure this port's memory allocation stays
+ * around until its child MSTB releases it
+ */
+ drm_dp_mst_get_port_malloc(port);
+ mutex_unlock(&mgr->lock);
- /* And make sure we send a link address for this */
- ret = 1;
- break;
+ /* And make sure we send a link address for this */
+ ret = 1;
+ }
}
out:
@@ -2133,9 +2150,8 @@ drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
goto error;
}
- 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_NONE &&
+ drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
port->cached_edid = drm_get_edid(port->connector,
&port->aux.ddc);
drm_connector_set_tile_property(port->connector);
@@ -2203,6 +2219,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port;
int old_ddps = 0, ret;
u8 new_pdt = DP_PEER_DEVICE_NONE;
+ bool new_mcs = 0;
bool created = false, send_link_addr = false, changed = false;
port = drm_dp_get_port(mstb, port_msg->port_number);
@@ -2247,7 +2264,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
port->input = port_msg->input_port;
if (!port->input)
new_pdt = port_msg->peer_device_type;
- port->mcs = port_msg->mcs;
+ new_mcs = port_msg->mcs;
port->ddps = port_msg->ddps;
port->ldps = port_msg->legacy_device_plug_status;
port->dpcd_rev = port_msg->dpcd_revision;
@@ -2275,7 +2292,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
}
}
- ret = drm_dp_port_set_pdt(port, new_pdt);
+ ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
if (ret == 1) {
send_link_addr = true;
} else if (ret < 0) {
@@ -2289,7 +2306,8 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
* we're coming out of suspend. In this case, always resend the link
* address if there's an MSTB on this port
*/
- if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING)
+ if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
+ port->mcs)
send_link_addr = true;
if (port->connector)
@@ -2326,6 +2344,7 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port;
int old_ddps, old_input, ret, i;
u8 new_pdt;
+ bool new_mcs;
bool dowork = false, create_connector = false;
port = drm_dp_get_port(mstb, conn_stat->port_number);
@@ -2357,7 +2376,6 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
old_ddps = port->ddps;
old_input = port->input;
port->input = conn_stat->input_port;
- port->mcs = conn_stat->message_capability_status;
port->ldps = conn_stat->legacy_device_plug_status;
port->ddps = conn_stat->displayport_device_plug_status;
@@ -2370,8 +2388,8 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
}
new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
-
- ret = drm_dp_port_set_pdt(port, new_pdt);
+ new_mcs = conn_stat->message_capability_status;
+ ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
if (ret == 1) {
dowork = true;
} else if (ret < 0) {
@@ -3938,6 +3956,8 @@ drm_dp_mst_detect_port(struct drm_connector *connector,
switch (port->pdt) {
case DP_PEER_DEVICE_NONE:
case DP_PEER_DEVICE_MST_BRANCHING:
+ if (!port->mcs)
+ ret = connector_status_connected;
break;
case DP_PEER_DEVICE_SST_SINK:
@@ -4572,7 +4592,7 @@ drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
if (port->connector)
port->mgr->cbs->destroy_connector(port->mgr, port->connector);
- drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE);
+ drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
drm_dp_mst_put_port_malloc(port);
}
--
2.17.1
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