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[RFC,v3,3/3] ALSA: Documentation about HDA DP MST pin init and connection

Message ID 1476344977-147193-4-git-send-email-libin.yang@linux.intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

libin.yang@linux.intel.com Oct. 13, 2016, 7:49 a.m. UTC 
From: Libin Yang <libin.yang@linux.intel.com>

Add the documentation about HD-audio DP MST:
1. pin initialization
2. device entry connection list

Signed-off-by: Libin Yang <libin.yang@linux.intel.com>
---
 Documentation/sound/alsa/HD-Audio-DP-MST-audio.txt | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
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Patch

diff --git a/Documentation/sound/alsa/HD-Audio-DP-MST-audio.txt b/Documentation/sound/alsa/HD-Audio-DP-MST-audio.txt
index 82744ac..0c5ea7d 100644
--- a/Documentation/sound/alsa/HD-Audio-DP-MST-audio.txt
+++ b/Documentation/sound/alsa/HD-Audio-DP-MST-audio.txt
@@ -15,6 +15,23 @@  PCM
 ===
 To be added
 
+Pin Initialization
+==================
+Each pin may have several device entries (virtual pins). On Intel platform,
+the device entries number is dynamically changed. If DP MST hub is connected,
+it is in DP MST mode, and the device entries number is 3. Otherwise, the
+device entries number is 1.
+
+To simplify the implementation, all the device entries will be initialized
+when bootup no matter whether it is in DP MST mode or not.
+
+Connection list
+===============
+DP MST reuses connection list code. The code can be reused because
+device entries on the same pin have the same connection list.
+
+This means DP MST gets the device entry connection list without the
+device entry setting.
 
 Jack
 ====