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[v5,3/3] ALSA: Documentation about HDA DP MST pin init and connection

Message ID 1484208294-8637-4-git-send-email-libin.yang@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Yang, Libin Jan. 12, 2017, 8:04 a.m. UTC 
From: Libin Yang <libin.yang@intel.com>

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

Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Libin Yang <libin.yang@intel.com>
---
 Documentation/sound/hd-audio/dp-mst.rst | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
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Patch

diff --git a/Documentation/sound/hd-audio/dp-mst.rst b/Documentation/sound/hd-audio/dp-mst.rst
index 58b7243..1617459 100644
--- a/Documentation/sound/hd-audio/dp-mst.rst
+++ b/Documentation/sound/hd-audio/dp-mst.rst
@@ -19,6 +19,23 @@  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
 ====