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From:   Sam McNally <sammc@chromium.org>
To:     LKML <linux-kernel@vger.kernel.org>
Cc:     Hans Verkuil <hverkuil@xs4all.nl>, Lyude Paul <lyude@redhat.com>,
        Sam McNally <sammc@chromium.org>,
        Anshuman Gupta <anshuman.gupta@intel.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        David Airlie <airlied@linux.ie>,
        Lee Jones <lee.jones@linaro.org>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Sean Paul <seanpaul@chromium.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        dri-devel@lists.freedesktop.org
Subject: [PATCH v4 2/3] drm/dp_mst: Add support for sink event notify messages
Date:   Tue, 18 May 2021 22:35:29 +1000
Message-Id: <20210518223508.v4.2.I8693156f555875e5c8342e86ab37ce968dfdd277@changeid>
In-Reply-To: <20210518223508.v4.1.I6f50a7996687318ba298c24a3663c8be7dd432c7@changeid>
References: <20210518223508.v4.1.I6f50a7996687318ba298c24a3663c8be7dd432c7@changeid>
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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@chromium.org>
---

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 22aaedc63aec..84b1411460d7 100644
--- a/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
+++ b/drivers/gpu/drm/selftests/test-drm_dp_mst_helper.c
@@ -163,6 +163,7 @@ 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)) {
@@ -385,10 +386,17 @@ 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;
-- 
2.31.1.751.gd2f1c929bd-goog