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drm/dp/mst: move GUID storage from mgr, port to only mst branch
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Previous implementation does not handle case below: boot up one MST branch
to DP connector of ASIC. After boot up, hot plug 2nd MST branch to DP output
of 1st MST, GUID is not created for 2nd MST branch. When downstream port of
2nd MST branch send upstream request, it fails because 2nd MST branch GUID
is not available.

New Implementation: only create GUID for MST branch and save it within Branch.

Signed-off-by: Hersen Wu <[email protected]>
Reviewed-by: Harry Wentland <[email protected]>
Cc: [email protected]
Acked-by: Alex Deucher <[email protected]>
Signed-off-by: Dave Airlie <[email protected]>
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@airlied
Hersen Wu authored and airlied committed Feb 5, 2016
1 parent cfcfa08 commit 5e93b82
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Showing 2 changed files with 38 additions and 51 deletions.
64 changes: 28 additions & 36 deletions drivers/gpu/drm/drm_dp_mst_topology.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1018,18 +1018,27 @@ static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
return send_link;
}

static void drm_dp_check_port_guid(struct drm_dp_mst_branch *mstb,
struct drm_dp_mst_port *port)
static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
{
int ret;
if (port->dpcd_rev >= 0x12) {
port->guid_valid = drm_dp_validate_guid(mstb->mgr, port->guid);
if (!port->guid_valid) {
ret = drm_dp_send_dpcd_write(mstb->mgr,
port,
DP_GUID,
16, port->guid);
port->guid_valid = true;

memcpy(mstb->guid, guid, 16);

if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
if (mstb->port_parent) {
ret = drm_dp_send_dpcd_write(
mstb->mgr,
mstb->port_parent,
DP_GUID,
16,
mstb->guid);
} else {

ret = drm_dp_dpcd_write(
mstb->mgr->aux,
DP_GUID,
mstb->guid,
16);
}
}
}
Expand Down Expand Up @@ -1086,7 +1095,6 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
port->dpcd_rev = port_msg->dpcd_revision;
port->num_sdp_streams = port_msg->num_sdp_streams;
port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
memcpy(port->guid, port_msg->peer_guid, 16);

/* manage mstb port lists with mgr lock - take a reference
for this list */
Expand All @@ -1099,11 +1107,9 @@ static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,

if (old_ddps != port->ddps) {
if (port->ddps) {
drm_dp_check_port_guid(mstb, port);
if (!port->input)
drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
} else {
port->guid_valid = false;
port->available_pbn = 0;
}
}
Expand Down Expand Up @@ -1161,9 +1167,7 @@ static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
if (old_ddps != port->ddps) {
dowork = true;
if (port->ddps) {
drm_dp_check_port_guid(mstb, port);
} else {
port->guid_valid = false;
port->available_pbn = 0;
}
}
Expand Down Expand Up @@ -1220,13 +1224,14 @@ static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
struct drm_dp_mst_branch *found_mstb;
struct drm_dp_mst_port *port;

if (memcmp(mstb->guid, guid, 16) == 0)
return mstb;


list_for_each_entry(port, &mstb->ports, next) {
if (!port->mstb)
continue;

if (port->guid_valid && memcmp(port->guid, guid, 16) == 0)
return port->mstb;

found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);

if (found_mstb)
Expand All @@ -1245,10 +1250,7 @@ static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
/* find the port by iterating down */
mutex_lock(&mgr->lock);

if (mgr->guid_valid && memcmp(mgr->guid, guid, 16) == 0)
mstb = mgr->mst_primary;
else
mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);

if (mstb)
kref_get(&mstb->kref);
Expand Down Expand Up @@ -1566,6 +1568,9 @@ static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
}

drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);

for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
}
Expand Down Expand Up @@ -2006,20 +2011,6 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms
goto out_unlock;
}


/* sort out guid */
ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, mgr->guid, 16);
if (ret != 16) {
DRM_DEBUG_KMS("failed to read DP GUID %d\n", ret);
goto out_unlock;
}

mgr->guid_valid = drm_dp_validate_guid(mgr, mgr->guid);
if (!mgr->guid_valid) {
ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, mgr->guid, 16);
mgr->guid_valid = true;
}

queue_work(system_long_wq, &mgr->work);

ret = 0;
Expand Down Expand Up @@ -2241,6 +2232,7 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
}

drm_dp_update_port(mstb, &msg.u.conn_stat);

DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
} else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
Expand Down
25 changes: 10 additions & 15 deletions include/drm/drm_dp_mst_helper.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -44,8 +44,6 @@ struct drm_dp_vcpi {
/**
* struct drm_dp_mst_port - MST port
* @kref: reference count for this port.
* @guid_valid: for DP 1.2 devices if we have validated the GUID.
* @guid: guid for DP 1.2 device on this port.
* @port_num: port number
* @input: if this port is an input port.
* @mcs: message capability status - DP 1.2 spec.
Expand All @@ -70,10 +68,6 @@ struct drm_dp_vcpi {
struct drm_dp_mst_port {
struct kref kref;

/* if dpcd 1.2 device is on this port - its GUID info */
bool guid_valid;
u8 guid[16];

u8 port_num;
bool input;
bool mcs;
Expand Down Expand Up @@ -110,10 +104,12 @@ struct drm_dp_mst_port {
* @tx_slots: transmission slots for this device.
* @last_seqno: last sequence number used to talk to this.
* @link_address_sent: if a link address message has been sent to this device yet.
* @guid: guid for DP 1.2 branch device. port under this branch can be
* identified by port #.
*
* This structure represents an MST branch device, there is one
* primary branch device at the root, along with any others connected
* to downstream ports
* primary branch device at the root, along with any other branches connected
* to downstream port of parent branches.
*/
struct drm_dp_mst_branch {
struct kref kref;
Expand All @@ -132,6 +128,9 @@ struct drm_dp_mst_branch {
struct drm_dp_sideband_msg_tx *tx_slots[2];
int last_seqno;
bool link_address_sent;

/* global unique identifier to identify branch devices */
u8 guid[16];
};


Expand Down Expand Up @@ -406,11 +405,9 @@ struct drm_dp_payload {
* @conn_base_id: DRM connector ID this mgr is connected to.
* @down_rep_recv: msg receiver state for down replies.
* @up_req_recv: msg receiver state for up requests.
* @lock: protects mst state, primary, guid, dpcd.
* @lock: protects mst state, primary, dpcd.
* @mst_state: if this manager is enabled for an MST capable port.
* @mst_primary: pointer to the primary branch device.
* @guid_valid: GUID valid for the primary branch device.
* @guid: GUID for primary port.
* @dpcd: cache of DPCD for primary port.
* @pbn_div: PBN to slots divisor.
*
Expand All @@ -432,13 +429,11 @@ struct drm_dp_mst_topology_mgr {
struct drm_dp_sideband_msg_rx up_req_recv;

/* pointer to info about the initial MST device */
struct mutex lock; /* protects mst_state + primary + guid + dpcd */
struct mutex lock; /* protects mst_state + primary + dpcd */

bool mst_state;
struct drm_dp_mst_branch *mst_primary;
/* primary MST device GUID */
bool guid_valid;
u8 guid[16];

u8 dpcd[DP_RECEIVER_CAP_SIZE];
u8 sink_count;
int pbn_div;
Expand Down

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