ALSA: hda-intel - add special 'hwio' model to bypass initialization

Using the 'model=hwio' option, the driver bypasses any codec
initialization and the reset procedure for codecs is also
bypassed. This mode is usefull to enable direct access using
hwdep interface (using hdaverb or hda-analyzer tools) and
retain codec setup from BIOS.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

1 files changed, 5 insertions, 0 deletions

diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt
index f4dd3bf99d1..ecacf53a865 100644
--- a/Documentation/sound/alsa/HD-Audio.txt
+++ b/Documentation/sound/alsa/HD-Audio.txt
@@ -196,6 +196,11 @@ generic parser regardless of the codec.  Usually the codec-specific
 parser is much better than the generic parser (as now).  Thus this
 option is more about the debugging purpose.
 
+Another special meaning has 'model=hwio'. For this model, the driver
+bypasses any codec initialization and the reset procedure for codecs
+is also bypassed. This mode is usefull to enable direct access using
+hwdep interface (using hdaverb or hda-analyzer tools) and retain
+codec setup from BIOS.
 
 Speaker and Headphone Output
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~