From dd48e8ed3bfdee879ce60508230bed7fb2ca5fa8 Mon Sep 17 00:00:00 2001 From: Libin Yang Date: Thu, 12 Jan 2017 16:04:54 +0800 Subject: [PATCH] ALSA: Documentation about HDA DP MST pin init and connection Add the documentation about HD-audio DP MST: 1. pin initialization 2. device entry connection list Reviewed-by: Takashi Iwai Signed-off-by: Libin Yang Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1484208294-8637-4-git-send-email-libin.yang@intel.com --- Documentation/sound/hd-audio/dp-mst.rst | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/Documentation/sound/hd-audio/dp-mst.rst b/Documentation/sound/hd-audio/dp-mst.rst index 58b72437e6c3e..1617459e332fd 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 ==== -- 2.39.5