To help in debugging issues with DisplayPort Multi-Stream Transport (aka
DP-MST) support, print information of active connections for each device
of a display audio pin widget.
Example output with the patch with two monitors connected to a DP-MST hub:
Devices: 4
Dev 00: PD = 0, ELDV = 0, IA = 0, Connections [ 0x03* 0x05 0x07 0x09 ]
Dev 01: PD = 1, ELDV = 1, IA = 0, Connections [ 0x03* 0x05 0x07 0x09 ]
*Dev 02: PD = 1, ELDV = 1, IA = 0, Connections [ 0x03 0x05* 0x07 0x09 ]
Dev 03: PD = 0, ELDV = 0, IA = 0, Connections [ 0x03* 0x05 0x07 0x09 ]
Connection: 4
0x03 0x05* 0x07 0x09
Format of existing "Connection:" entry is left intact to keep
compatibility.
Signed-off-by: Kai Vehmanen <kai.vehmanen@xxxxxxxxxxxxxxx>
---
sound/pci/hda/hda_proc.c | 38 +++++++++++++++++++++++++++++++++++++-
1 file changed, 37 insertions(+), 1 deletion(-)
v2 changes:
- add NULL check to conn array allocation
- put a few functions to a single line as they fit within 100 columns
- reformat the first paragraph of commit message
diff --git a/sound/pci/hda/hda_proc.c b/sound/pci/hda/hda_proc.c
index 0631f31ef87f..00c2eeb2c472 100644
--- a/sound/pci/hda/hda_proc.c
+++ b/sound/pci/hda/hda_proc.c
@@ -679,6 +679,38 @@ static void print_gpio(struct snd_info_buffer *buffer,
print_nid_array(buffer, codec, nid, &codec->nids);
}
+static void print_dpmst_connections(struct snd_info_buffer *buffer, struct hda_codec *codec,
+ hda_nid_t nid, int dev_num)
+{
+ int c, conn_len, curr, dev_id_saved;
+ hda_nid_t *conn;
+
+ conn_len = snd_hda_get_num_raw_conns(codec, nid);
+ if (conn_len <= 0)
+ return;
+
+ conn = kmalloc_array(conn_len, sizeof(hda_nid_t), GFP_KERNEL);
+ if (!conn)
+ return;
+
+ dev_id_saved = snd_hda_get_dev_select(codec, nid);
+
+ snd_hda_set_dev_select(codec, nid, dev_num);
+ curr = snd_hda_codec_read(codec, nid, 0, AC_VERB_GET_CONNECT_SEL, 0);
+ if (snd_hda_get_raw_connections(codec, nid, conn, conn_len) < 0)
+ goto out;
+
+ for (c = 0; c < conn_len; c++) {
+ snd_iprintf(buffer, " 0x%02x", conn[c]);
+ if (c == curr)
+ snd_iprintf(buffer, "*");
+ }
+
+out:
+ kfree(conn);
+ snd_hda_set_dev_select(codec, nid, dev_id_saved);
+}
+
static void print_device_list(struct snd_info_buffer *buffer,
struct hda_codec *codec, hda_nid_t nid)
{
@@ -702,10 +734,14 @@ static void print_device_list(struct snd_info_buffer *buffer,
snd_iprintf(buffer, " ");
snd_iprintf(buffer,
- "Dev %02d: PD = %d, ELDV = %d, IA = %d\n", i,
+ "Dev %02d: PD = %d, ELDV = %d, IA = %d, Connections [", i,
!!(dev_list[i] & AC_DE_PD),
!!(dev_list[i] & AC_DE_ELDV),
!!(dev_list[i] & AC_DE_IA));
+
+ print_dpmst_connections(buffer, codec, nid, i);
+
+ snd_iprintf(buffer, " ]\n");
}
}
--
2.28.0
