[PATCH v4 2/3] drm/dp/mst: Enhance DP MST debugfs output

[Jim Bride]

Add some additional information (input vs. output port, sink associated
with VC, peer device type, max number of VCs supported) and ensure that
any embedded '\0' characters in a branch device's devid string are not
written to debugfs.

v2: Rebase + change drm_edid_get_monitor_name() call to reflect new
    signature.

v3: Minor changes suggested by Jani + rebase.

v4: Rebase

cc: dri-devel at lists.freedesktop.org
cc: Jani Nikula <jani.nikula at linux.intel.com>
Reviewed-by: Jani Nikula <jani.nikula at intel.com>
Signed-off-by: Jim Bride <jim.bride at linux.intel.com>
---
 drivers/gpu/drm/drm_dp_mst_topology.c | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 27fbd79..06d8b0a 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -2729,7 +2729,7 @@ static void drm_dp_mst_dump_mstb(struct seq_file *m,
 
 	seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
 	list_for_each_entry(port, &mstb->ports, next) {
-		seq_printf(m, "%sport: %d: ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
+		seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
 		if (port->mstb)
 			drm_dp_mst_dump_mstb(m, port->mstb);
 	}
@@ -2750,6 +2750,16 @@ static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
 	return false;
 }
 
+static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
+			       struct drm_dp_mst_port *port, char *name,
+			       int namelen)
+{
+	struct edid *mst_edid;
+
+	mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
+	drm_edid_get_monitor_name(mst_edid, name, namelen);
+}
+
 /**
  * drm_dp_mst_dump_topology(): dump topology to seq file.
  * @m: seq_file to dump output to
@@ -2762,6 +2772,7 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
 {
 	int i;
 	struct drm_dp_mst_port *port;
+
 	mutex_lock(&mgr->lock);
 	if (mgr->mst_primary)
 		drm_dp_mst_dump_mstb(m, mgr->mst_primary);
@@ -2770,14 +2781,21 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
 	mutex_unlock(&mgr->lock);
 
 	mutex_lock(&mgr->payload_lock);
-	seq_printf(m, "vcpi: %lx %lx\n", mgr->payload_mask, mgr->vcpi_mask);
+	seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
+		mgr->max_payloads);
 
 	for (i = 0; i < mgr->max_payloads; i++) {
 		if (mgr->proposed_vcpis[i]) {
+			char name[14];
+
 			port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
-			seq_printf(m, "vcpi %d: %d %d %d\n", i, port->port_num, port->vcpi.vcpi, port->vcpi.num_slots);
+			fetch_monitor_name(mgr, port, name, sizeof(name));
+			seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
+				   port->port_num, port->vcpi.vcpi,
+				   port->vcpi.num_slots,
+				   (*name != 0) ? name :  "Unknown");
 		} else
-			seq_printf(m, "vcpi %d:unsed\n", i);
+			seq_printf(m, "vcpi %d:unused\n", i);
 	}
 	for (i = 0; i < mgr->max_payloads; i++) {
 		seq_printf(m, "payload %d: %d, %d, %d\n",
@@ -2817,8 +2835,9 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
 		for (i = 0; i < 0x3; i++)
 			seq_printf(m, "%02x", buf[i]);
 		seq_printf(m, " devid: ");
-		for (i = 0x3; i < 0x8; i++)
+		for (i = 0x3; i < 0x8 && buf[i]; i++)
 			seq_printf(m, "%c", buf[i]);
+
 		seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
 		seq_printf(m, "\n");
 		bret = dump_dp_payload_table(mgr, buf);
-- 
2.5.0