Alsa problems: can't use dmix

[feng_tian <feng_tian@126.com>]

Hi, all:
I have a problem with dmix of alsa.
I'm using alsa v1.0.11rc2 now. And make it running on ATMEL AT91SAM9260EK board. It runs ok without Dmix. But when I tried:
bash> aplay -D dmixer test.wav
The errors are:

ALSA lib pcm_direct.c:790:(snd_pcm_direct_initialize_slave) slave plugin does not support mmap interleaved or mmap noninterleaved access
ALSA lib pcm_dmix.c:864:(snd_pcm_dmix_open) unable to initialize slave
aplay: main:547: audio open error: Invalid argument

The configuration of my alsa in /etc/asound.con is:

pcm.card0 {
type hw
card 0
}

pcm.!default {
type plug
slave.pcm "dmixer"
}

pcm.dmixer {
type dmix
ipc_key 1024
slave {
pcm "hw:0,0"
format S16_LE
period_time 0
period_size 1024
buffer_size 4096

rate 22050
}
bindings {
0 0
1 1
}
}
ctl.dmixer {
type hw
card 0
device 0
}
pcm.dsp {
type plug
slave.pcm "dmixer" #use our new PCM here
}
ctl.mixer{
type hw
card 0
}



bash> aplay -L
gives:

PCM list:
hw {
@args.0 CARD
@args.1 DEV
@args.2 SUBDEV
@args.CARD {
type string
default {
@func getenv
vars {
0 ALSA_PCM_CARD
1 ALSA_CARD
}
default {
@func refer
name 'defaults.pcm.card'
}
}
}
@args.DEV {
type integer
default {
@func igetenv
vars {
0 ALSA_PCM_DEVICE
}
default {
@func refer
name 'defaults.pcm.device'
}
}
}
@args.SUBDEV {
type integer
default {
@func refer
name 'defaults.pcm.subdevice'
}
}
type hw
card $CARD
device $DEV
subdevice $SUBDEV
}
plughw {
@args.0 CARD
@args.1 DEV
@args.2 SUBDEV
@args.CARD {
type string
default {
@func getenv
vars {
0 ALSA_PCM_CARD
1 ALSA_CARD
}
default {
@func refer
name 'defaults.pcm.card'
}
}
}
@args.DEV {
type integer
default {
@func igetenv
vars {
0 ALSA_PCM_DEVICE
}
default {
@func refer
name 'defaults.pcm.device'
}
}
}
@args.SUBDEV {
type integer
default {
@func refer
name 'defaults.pcm.subdevice'
}
}
type plug
slave.pcm {
type hw
card $CARD
device $DEV
subdevice $SUBDEV
}
}
plug {
@args.0 SLAVE
@args.SLAVE {
type string
}
type plug
slave.pcm $SLAVE
}
shm {
@args.0 SOCKET
@args.1 PCM
@args.SOCKET {
type string
}
@args.PCM {
type string
}
type shm
server $SOCKET
pcm $PCM
}
tee {
@args.0 SLAVE
@args.1 FILE
@args.2 FORMAT
@args.SLAVE {
type string
}
@args.FILE {
type string
}
@args.FORMAT {
type string
default raw
}
type file
slave.pcm $SLAVE
file $FILE
format $FORMAT
}
file {
@args.0 FILE
@args.1 FORMAT
@args.FILE {
type string
}
@args.FORMAT {
type string
default raw
}
type file
slave.pcm null
file $FILE
format $FORMAT
}
null {
type null
}
cards 'cards.pcm'
front 'cards.pcm.front'
rear 'cards.pcm.rear'
center_lfe 'cards.pcm.center_lfe'
side 'cards.pcm.side'
surround40 'cards.pcm.surround40'
surround41 'cards.pcm.surround41'
surround50 'cards.pcm.surround50'
surround51 'cards.pcm.surround51'
surround71 'cards.pcm.surround71'
iec958 'cards.pcm.iec958'
spdif 'cards.pcm.iec958'
modem 'cards.pcm.modem'
phoneline 'cards.pcm.phoneline'
dmix 'cards.pcm.dmix'
dsnoop 'cards.pcm.dsnoop'
card0 {
type hw
card 0
}
default {
type plug
slave.pcm dmixer
}
dmixer {
type dmix
ipc_key 1024
slave {
pcm 'hw:0,0'
format S16_LE
period_time 0
period_size 1024
buffer_size 4096
rate 22050
}
bindings {
0 0
1 1
}
}
dsp {
type plug
slave.pcm dmixer
}
Any helps or advices is wecome.

BR
Feng