Merge tag 'topic/mst-bw-check-fixes-for-airlied-2020-03-12-2' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

UAPI Changes: None

Cross-subsystem Changes: None

Core Changes: Fixed regressions introduced by commit cd82d82cbc
("drm/dp_mst: Add branch bandwidth validation to MST atomic check"),
which would cause us to:

* Calculate the available bandwidth on an MST topology incorrectly, and
  as a result reject most display configurations that would try to enable
  more then one sink on a topology
* Occasionally expose MST connectors to userspace before finishing
  probing their PBN capabilities, resulting in us rejecting display
  configurations because we assumed briefly that no bandwidth was
  available

Driver Changes: None

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/bf16ee577567beed91c86b7d9cda3ec2e8c50a71.camel@redhat.com
This commit is contained in:
Dave Airlie 2020-03-13 10:38:24 +10:00
commit 16b78f052d
2 changed files with 130 additions and 62 deletions

View File

@ -1935,7 +1935,7 @@ static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
return parent_lct + 1;
}
static bool drm_dp_mst_is_dp_mst_end_device(u8 pdt, bool mcs)
static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
{
switch (pdt) {
case DP_PEER_DEVICE_DP_LEGACY_CONV:
@ -1965,13 +1965,13 @@ drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
/* Teardown the old pdt, if there is one */
if (port->pdt != DP_PEER_DEVICE_NONE) {
if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
if (drm_dp_mst_is_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)) {
drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
port->pdt = new_pdt;
port->mcs = new_mcs;
return 0;
@ -1991,7 +1991,7 @@ drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
port->mcs = new_mcs;
if (port->pdt != DP_PEER_DEVICE_NONE) {
if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
/* add i2c over sideband */
ret = drm_dp_mst_register_i2c_bus(&port->aux);
} else {
@ -2172,7 +2172,7 @@ drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
}
if (port->pdt != DP_PEER_DEVICE_NONE &&
drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
port->cached_edid = drm_get_edid(port->connector,
&port->aux.ddc);
drm_connector_set_tile_property(port->connector);
@ -2302,14 +2302,18 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
mutex_unlock(&mgr->lock);
}
if (old_ddps != port->ddps) {
if (port->ddps) {
if (!port->input) {
drm_dp_send_enum_path_resources(mgr, mstb,
port);
}
/*
* Reprobe PBN caps on both hotplug, and when re-probing the link
* for our parent mstb
*/
if (old_ddps != port->ddps || !created) {
if (port->ddps && !port->input) {
ret = drm_dp_send_enum_path_resources(mgr, mstb,
port);
if (ret == 1)
changed = true;
} else {
port->available_pbn = 0;
port->full_pbn = 0;
}
}
@ -2401,11 +2405,10 @@ drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
port->ddps = conn_stat->displayport_device_plug_status;
if (old_ddps != port->ddps) {
if (port->ddps) {
dowork = true;
} else {
port->available_pbn = 0;
}
if (port->ddps && !port->input)
drm_dp_send_enum_path_resources(mgr, mstb, port);
else
port->full_pbn = 0;
}
new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
@ -2556,13 +2559,6 @@ static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mg
if (port->input || !port->ddps)
continue;
if (!port->available_pbn) {
drm_modeset_lock(&mgr->base.lock, NULL);
drm_dp_send_enum_path_resources(mgr, mstb, port);
drm_modeset_unlock(&mgr->base.lock);
changed = true;
}
if (port->mstb)
mstb_child = drm_dp_mst_topology_get_mstb_validated(
mgr, port->mstb);
@ -2990,6 +2986,7 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
if (ret > 0) {
ret = 0;
path_res = &txmsg->reply.u.path_resources;
if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
@ -3002,14 +2999,22 @@ drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
path_res->port_number,
path_res->full_payload_bw_number,
path_res->avail_payload_bw_number);
port->available_pbn =
path_res->avail_payload_bw_number;
/*
* If something changed, make sure we send a
* hotplug
*/
if (port->full_pbn != path_res->full_payload_bw_number ||
port->fec_capable != path_res->fec_capable)
ret = 1;
port->full_pbn = path_res->full_payload_bw_number;
port->fec_capable = path_res->fec_capable;
}
}
kfree(txmsg);
return 0;
return ret;
}
static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
@ -3596,13 +3601,9 @@ drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
/* The link address will need to be re-sent on resume */
mstb->link_address_sent = false;
list_for_each_entry(port, &mstb->ports, next) {
/* The PBN for each port will also need to be re-probed */
port->available_pbn = 0;
list_for_each_entry(port, &mstb->ports, next)
if (port->mstb)
drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
}
}
/**
@ -4829,41 +4830,102 @@ static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
return false;
}
static inline
int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
struct drm_dp_mst_topology_state *mst_state)
static int
drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
struct drm_dp_mst_topology_state *state);
static int
drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_topology_state *state)
{
struct drm_dp_mst_port *port;
struct drm_dp_vcpi_allocation *vcpi;
int pbn_limit = 0, pbn_used = 0;
struct drm_dp_mst_port *port;
int pbn_used = 0, ret;
bool found = false;
list_for_each_entry(port, &branch->ports, next) {
if (port->mstb)
if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
return -ENOSPC;
if (port->available_pbn > 0)
pbn_limit = port->available_pbn;
}
DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch has %d PBN available\n",
branch, pbn_limit);
list_for_each_entry(vcpi, &mst_state->vcpis, next) {
if (!vcpi->pbn)
/* Check that we have at least one port in our state that's downstream
* of this branch, otherwise we can skip this branch
*/
list_for_each_entry(vcpi, &state->vcpis, next) {
if (!vcpi->pbn ||
!drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb))
continue;
if (drm_dp_mst_port_downstream_of_branch(vcpi->port, branch))
pbn_used += vcpi->pbn;
found = true;
break;
}
DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch used %d PBN\n",
branch, pbn_used);
if (!found)
return 0;
if (pbn_used > pbn_limit) {
DRM_DEBUG_ATOMIC("[MST BRANCH:%p] No available bandwidth\n",
branch);
if (mstb->port_parent)
DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
mstb->port_parent->parent, mstb->port_parent,
mstb);
else
DRM_DEBUG_ATOMIC("[MSTB:%p] Checking bandwidth limits\n",
mstb);
list_for_each_entry(port, &mstb->ports, next) {
ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
if (ret < 0)
return ret;
pbn_used += ret;
}
return pbn_used;
}
static int
drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
struct drm_dp_mst_topology_state *state)
{
struct drm_dp_vcpi_allocation *vcpi;
int pbn_used = 0;
if (port->pdt == DP_PEER_DEVICE_NONE)
return 0;
if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
bool found = false;
list_for_each_entry(vcpi, &state->vcpis, next) {
if (vcpi->port != port)
continue;
if (!vcpi->pbn)
return 0;
found = true;
break;
}
if (!found)
return 0;
/* This should never happen, as it means we tried to
* set a mode before querying the full_pbn
*/
if (WARN_ON(!port->full_pbn))
return -EINVAL;
pbn_used = vcpi->pbn;
} else {
pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
state);
if (pbn_used <= 0)
return pbn_used;
}
if (pbn_used > port->full_pbn) {
DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
port->parent, port, pbn_used,
port->full_pbn);
return -ENOSPC;
}
return 0;
DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
port->parent, port, pbn_used, port->full_pbn);
return pbn_used;
}
static inline int
@ -5061,9 +5123,15 @@ int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
if (ret)
break;
ret = drm_dp_mst_atomic_check_bw_limit(mgr->mst_primary, mst_state);
if (ret)
mutex_lock(&mgr->lock);
ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
mst_state);
mutex_unlock(&mgr->lock);
if (ret < 0)
break;
else
ret = 0;
}
return ret;

View File

@ -81,7 +81,7 @@ struct drm_dp_vcpi {
* &drm_dp_mst_topology_mgr.base.lock.
* @num_sdp_stream_sinks: Number of stream sinks. Protected by
* &drm_dp_mst_topology_mgr.base.lock.
* @available_pbn: Available bandwidth for this port. Protected by
* @full_pbn: Max possible bandwidth for this port. Protected by
* &drm_dp_mst_topology_mgr.base.lock.
* @next: link to next port on this branch device
* @aux: i2c aux transport to talk to device connected to this port, protected
@ -126,7 +126,7 @@ struct drm_dp_mst_port {
u8 dpcd_rev;
u8 num_sdp_streams;
u8 num_sdp_stream_sinks;
uint16_t available_pbn;
uint16_t full_pbn;
struct list_head next;
/**
* @mstb: the branch device connected to this port, if there is one.