[alsa-devel] [PATCH v2 3/5] ALSA: hda - Add DP-MST conn list support

[Nikhil Mahale]

Document change notification HDA040-A for the Intel High Definition
Audio 1.0a specification introduces a Device Select verb for Digital
Display Pin Widgets that are multi-stream capable. This verb selects
a Device Entry that is used by subsequent Pin Widget verbs,
including the Get Connection List Entry verb.

This patch queries the current Device Select value, associates it
with the connection list, and updates the connection list management
code to consider dev_id along with nid.

Signed-off-by: Nikhil Mahale <nmahale at nvidia.com>
Reviewed-by: Aaron Plattner <aplattner at nvidia.com>
---
 sound/pci/hda/hda_codec.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index a2fb19129219..8f32cab8f4a4 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -88,6 +88,7 @@ struct hda_conn_list {
 	struct list_head list;
 	int len;
 	hda_nid_t nid;
+	int dev_id;
 	hda_nid_t conns[0];
 };
 
@@ -96,8 +97,9 @@ static struct hda_conn_list *
 lookup_conn_list(struct hda_codec *codec, hda_nid_t nid)
 {
 	struct hda_conn_list *p;
+	int dev_id = snd_hda_get_dev_select(codec, nid);
 	list_for_each_entry(p, &codec->conn_list, list) {
-		if (p->nid == nid)
+		if (p->nid == nid && p->dev_id == dev_id)
 			return p;
 	}
 	return NULL;
@@ -113,6 +115,7 @@ static int add_conn_list(struct hda_codec *codec, hda_nid_t nid, int len,
 		return -ENOMEM;
 	p->len = len;
 	p->nid = nid;
+	p->dev_id = snd_hda_get_dev_select(codec, nid);
 	memcpy(p->conns, list, len * sizeof(hda_nid_t));
 	list_add(&p->list, &codec->conn_list);
 	return 0;
-- 
2.16.4