ALSA: hda - Add position_fix=4 (COMBO) option
This patch adds a new position_fix option value, 4, as a combo mode
to use LPIB for playbacks and POSBUF for captures. It's the way
recommended by Intel hardware guys.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt
index 936699e..9af64c5 100644
--- a/Documentation/sound/alsa/ALSA-Configuration.txt
+++ b/Documentation/sound/alsa/ALSA-Configuration.txt
@@ -860,7 +860,8 @@
[Multiple options for each card instance]
model - force the model name
- position_fix - Fix DMA pointer (0 = auto, 1 = use LPIB, 2 = POSBUF)
+ position_fix - Fix DMA pointer (0 = auto, 1 = use LPIB, 2 = POSBUF,
+ 3 = VIACOMBO, 4 = COMBO)
probe_mask - Bitmask to probe codecs (default = -1, meaning all slots)
When the bit 8 (0x100) is set, the lower 8 bits are used
as the "fixed" codec slots; i.e. the driver probes the
@@ -925,6 +926,11 @@
(Usually SD_LPIB register is more accurate than the
position buffer.)
+ position_fix=3 is specific to VIA devices. The position
+ of the capture stream is checked from both LPIB and POSBUF
+ values. position_fix=4 is a combination mode, using LPIB
+ for playback and POSBUF for capture.
+
NB: If you get many "azx_get_response timeout" messages at
loading, it's likely a problem of interrupts (e.g. ACPI irq
routing). Try to boot with options like "pci=noacpi". Also, you
diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt
index 91fee3b..7813c06 100644
--- a/Documentation/sound/alsa/HD-Audio.txt
+++ b/Documentation/sound/alsa/HD-Audio.txt
@@ -59,7 +59,12 @@
`position_fix=1` means to use LPIB method explicitly.
`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
+for some VIA controllers. The capture stream position is corrected
+by comparing both LPIB and position-buffer values.
+`position_fix=4` is another combination available for all controllers,
+and uses LPIB for the playback and the position-buffer for the capture
+streams.
+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.