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[ALSA] Support all sample rate conversion capabilities of DXS channels

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Documentation,VIA82xx driver
Add support for full sample rate conversion capabilities of DXS
channels present in VIA VT8233/5/7 controllers:

- any sample rate in the 8000 ... 48000 Hz range is supported even if
  the AC'97 codec supports only 48000 Hz output;

- different DXS channels can use different sample rates at the same
  time (the controller performs required sample rate conversion and
  mixing in hardware).

Signed-off-by: Sergey Vlasov <vsu@altlinux.ru>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Sergey Vlasov
2005-04-11 15:04:33 +02:00
committed by Jaroslav Kysela
parent 26be865923
commit 2d7eb7cb2b
2 changed files with 30 additions and 11 deletions
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21
Documentation/sound/alsa/ALSA-Configuration.txt
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@@ -1211,16 +1211,18 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
------------------
Module for AC'97 motherboards based on VIA 82C686A/686B, 8233,
8233A, 8233C, 8235 (south) bridge.
8233A, 8233C, 8235, 8237 (south) bridge.
mpu_port - 0x300,0x310,0x320,0x330, otherwise obtain BIOS setup
[VIA686A/686B only]
joystick - Enable joystick (default off) [VIA686A/686B only]
ac97_clock - AC'97 codec clock base (default 48000Hz)
dxs_support - support DXS channels,
0 = auto (defalut), 1 = enable, 2 = disable,
3 = 48k only, 4 = no VRA
[VIA8233/C,8235 only]
0 = auto (default), 1 = enable, 2 = disable,
3 = 48k only, 4 = no VRA, 5 = enable any sample
rate and different sample rates on different
channels
[VIA8233/C, 8235, 8237 only]
ac97_quirk - AC'97 workaround for strange hardware
See the description of intel8x0 module for details.
@@ -1232,18 +1234,21 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed.
default value 1.4. Then the interrupt number will be
assigned under 15. You might also upgrade your BIOS.
Note: VIA8233/5 (not VIA8233A) can support DXS (direct sound)
Note: VIA8233/5/7 (not VIA8233A) can support DXS (direct sound)
channels as the first PCM. On these channels, up to 4
streams can be played at the same time.
streams can be played at the same time, and the controller
can perform sample rate conversion with separate rates for
each channel.
As default (dxs_support = 0), 48k fixed rate is chosen
except for the known devices since the output is often
noisy except for 48k on some mother boards due to the
bug of BIOS.
Please try once dxs_support=1 and if it works on other
Please try once dxs_support=5 and if it works on other
sample rates (e.g. 44.1kHz of mp3 playback), please let us
know the PCI subsystem vendor/device id's (output of
"lspci -nv").
If it doesn't work, try dxs_support=4. If it still doesn't
If dxs_support=5 does not work, try dxs_support=1; if it
doesn't work too, try dxs_support=4. If it still doesn't
work and the default setting is ok, dxs_support=3 is the
right choice. If the default setting doesn't work at all,
try dxs_support=2 to disable the DXS channels.