ALSA: HDA: Add position_fix=3 module option, and refactor related code

What was previously known as via_dmapos_patch, and hard-coded to be
used for VIA and ATI controllers, is now configurable through a module
option. The background is that some VIA controllers seem to prefer
via_dmapos_patch to be turned off.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

1 files changed, 5 insertions, 3 deletions

diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt
index 278cc21..c82beb0 100644
--- a/Documentation/sound/alsa/HD-Audio.txt
+++ b/Documentation/sound/alsa/HD-Audio.txt
@@ -57,9 +57,11 @@ dead.  However, this detection isn't perfect on some devices.  In such
 a case, you can change the default method via `position_fix` option.
 
 `position_fix=1` means to use LPIB method explicitly.
-`position_fix=2` means to use the position-buffer.  0 is the default
-value, the automatic check and fallback to LPIB as described in the
-above.  If you get a problem of repeated sounds, this option might
+`position_fix=2` means to use the position-buffer.
+`position_fix=3` means to use a combination of both methods, needed
+for some VIA and ATI controllers.  0 is the default value for all other
+controllers, the automatic check and fallback to LPIB as described in
+the above.  If you get a problem of repeated sounds, this option might
 help.
 
 In addition to that, every controller is known to be broken regarding