[PATCH v5 2/3] drm/dp_mst: Add support for sink event notify messages

From: Sam McNally
Date: Mon May 24 2021 - 21:00:22 EST


Sink event notify messages are used for MST CEC IRQs. Add parsing
support for sink event notify messages in preparation for handling MST
CEC IRQs.

Signed-off-by: Sam McNally <sammc@xxxxxxxxxxxx>
---

(no changes since v4)

Changes in v4:
- Changed logging to use drm_dbg_kms()
- Added self-test

drivers/gpu/drm/drm_dp_mst_topology.c | 57 ++++++++++++++++++-
.../drm/selftests/test-drm_dp_mst_helper.c | 8 +++
include/drm/drm_dp_mst_helper.h | 14 +++++
3 files changed, 78 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 573f39a3dc16..29aad3b6b31a 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -473,6 +473,20 @@ drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
idx++;
break;
}
+ case DP_SINK_EVENT_NOTIFY: {
+ const struct drm_dp_sink_event_notify *msg;
+
+ msg = &req->u.sink_event;
+ buf[idx] = (msg->port_number & 0xf) << 4;
+ idx++;
+ memcpy(&raw->msg[idx], msg->guid, 16);
+ idx += 16;
+ buf[idx] = (msg->event_id & 0xff00) >> 8;
+ idx++;
+ buf[idx] = (msg->event_id & 0xff);
+ idx++;
+ break;
+ }
}
raw->cur_len = idx;
}
@@ -719,6 +733,12 @@ drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req
(int)ARRAY_SIZE(req->u.resource_stat.guid), req->u.resource_stat.guid,
req->u.resource_stat.available_pbn);
break;
+ case DP_SINK_EVENT_NOTIFY:
+ P("port=%d guid=%*ph event=%d",
+ req->u.sink_event.port_number,
+ (int)ARRAY_SIZE(req->u.sink_event.guid), req->u.sink_event.guid,
+ req->u.sink_event.event_id);
+ break;
default:
P("???\n");
break;
@@ -1163,6 +1183,30 @@ static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst
return false;
}

+static bool drm_dp_sideband_parse_sink_event_notify(const struct drm_dp_mst_topology_mgr *mgr,
+ struct drm_dp_sideband_msg_rx *raw,
+ struct drm_dp_sideband_msg_req_body *msg)
+{
+ int idx = 1;
+
+ msg->u.sink_event.port_number = (raw->msg[idx] & 0xf0) >> 4;
+ idx++;
+ if (idx > raw->curlen)
+ goto fail_len;
+
+ memcpy(msg->u.sink_event.guid, &raw->msg[idx], 16);
+ idx += 16;
+ if (idx > raw->curlen)
+ goto fail_len;
+
+ msg->u.sink_event.event_id = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
+ idx++;
+ return true;
+fail_len:
+ drm_dbg_kms(mgr->dev, "sink event notify parse length fail %d %d\n", idx, raw->curlen);
+ return false;
+}
+
bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr,
struct drm_dp_sideband_msg_rx *raw,
struct drm_dp_sideband_msg_req_body *msg)
@@ -1175,6 +1219,8 @@ bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr,
return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg);
case DP_RESOURCE_STATUS_NOTIFY:
return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg);
+ case DP_SINK_EVENT_NOTIFY:
+ return drm_dp_sideband_parse_sink_event_notify(mgr, raw, msg);
default:
drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n",
msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
@@ -4106,6 +4152,8 @@ drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
guid = msg->u.conn_stat.guid;
else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
guid = msg->u.resource_stat.guid;
+ else if (msg->req_type == DP_SINK_EVENT_NOTIFY)
+ guid = msg->u.sink_event.guid;

if (guid)
mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
@@ -4177,7 +4225,8 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg);

if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
- up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
+ up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY &&
+ up_req->msg.req_type != DP_SINK_EVENT_NOTIFY) {
drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n",
up_req->msg.req_type);
kfree(up_req);
@@ -4205,6 +4254,12 @@ static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n",
res_stat->port_number,
res_stat->available_pbn);
+ } else if (up_req->msg.req_type == DP_SINK_EVENT_NOTIFY) {
+ const struct drm_dp_sink_event_notify *sink_event =
+ &up_req->msg.u.sink_event;
+
+ drm_dbg_kms(mgr->dev, "Got SEN: pn: %d event_id %d\n",
+ sink_event->port_number, sink_event->event_id);
}

up_req->hdr = mgr->up_req_recv.initial_hdr;
diff --git a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
index 7bbeb1e5bc97..d49c10d52d88 100644
--- a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
+++ b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
@@ -164,6 +164,7 @@ sideband_msg_req_encode_decode(struct drm_dp_sideband_msg_req_body *in)
switch (in->req_type) {
case DP_CONNECTION_STATUS_NOTIFY:
case DP_RESOURCE_STATUS_NOTIFY:
+ case DP_SINK_EVENT_NOTIFY:
memcpy(&rxmsg->msg, txmsg->msg, ARRAY_SIZE(rxmsg->msg));
rxmsg->curlen = txmsg->cur_len;
if (!drm_dp_sideband_parse_req(mgr, rxmsg, out)) {
@@ -387,10 +388,17 @@ int igt_dp_mst_sideband_msg_req_decode(void *unused)
in.u.resource_stat.available_pbn = 0xcdef;
DO_TEST();

+ in.req_type = DP_SINK_EVENT_NOTIFY;
+ in.u.sink_event.port_number = 0xf;
+ get_random_bytes(in.u.sink_event.guid, sizeof(in.u.sink_event.guid));
+ in.u.sink_event.event_id = 0xcdef;
+ DO_TEST();
+
#undef DO_TEST
#define DO_TEST(req_type) FAIL_ON(!sideband_msg_req_parse(req_type))
DO_TEST(DP_CONNECTION_STATUS_NOTIFY);
DO_TEST(DP_RESOURCE_STATUS_NOTIFY);
+ DO_TEST(DP_SINK_EVENT_NOTIFY);

DO_TEST(DP_REMOTE_I2C_WRITE);
#undef DO_TEST
diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h
index c87a829b6498..96c87f761129 100644
--- a/include/drm/drm_dp_mst_helper.h
+++ b/include/drm/drm_dp_mst_helper.h
@@ -439,6 +439,19 @@ struct drm_dp_resource_status_notify {
u16 available_pbn;
};

+#define DP_SINK_EVENT_PANEL_REPLAY_ACTIVE_FRAME_CRC_ERROR BIT(0)
+#define DP_SINK_EVENT_PANEL_REPLAY_RFB_STORAGE_ERROR BIT(1)
+#define DP_SINK_EVENT_DSC_RC_BUFFER_UNDER_RUN BIT(2)
+#define DP_SINK_EVENT_DSC_RC_BUFFER_OVERFLOW BIT(3)
+#define DP_SINK_EVENT_DSC_CHUNK_LENGTH_ERROR BIT(4)
+#define DP_SINK_EVENT_CEC_IRQ_EVENT BIT(5)
+
+struct drm_dp_sink_event_notify {
+ u8 port_number;
+ u8 guid[16];
+ u16 event_id;
+};
+
struct drm_dp_query_payload_ack_reply {
u8 port_number;
u16 allocated_pbn;
@@ -450,6 +463,7 @@ struct drm_dp_sideband_msg_req_body {
struct drm_dp_connection_status_notify conn_stat;
struct drm_dp_port_number_req port_num;
struct drm_dp_resource_status_notify resource_stat;
+ struct drm_dp_sink_event_notify sink_event;

struct drm_dp_query_payload query_payload;
struct drm_dp_allocate_payload allocate_payload;
--
2.31.1.818.g46aad6cb9e-goog