hello everone.

i am now debuging the multi-channel device on my embeded board with alsa-lib.The version alsa-driver and alsa-lib is 1.0.24.

----------------------------->

zz@board:$ ls /dev/snd/

by-path controlC0 midiC0D0 pcmC0D0c pcmC0D0p pcmC0D1p seq timer

<---------------------------

i edit the asoundrc configure file.like this:

--------------------------------------------------->

pcm.!default{

type hw

card 0

}

ctl.!default{

type hw

card 0

}

#################################

## create a virtul device which has 4 channels for playback.

#################################

pcm.multi_playback{

type multi;

slaves.a.pcm "hw:0,0";

slaves.a.channels 2;

slaves.b.pcm "hw:0,1";

slaves.b.channels 2;

bindings.0.slave a;

bindings.0.channel 0;

bindings.1.slave a;

bindings.1.channel 1;

bindings.2.slave b;

bindings.2.channel 0;

bindings.3.slave b;

bindings.3.channel 1;

}

ctl.multi_playback{

type hw;

card 0;

}

pcm.ttable{

type route;

slave.pcm "multi_playback";

slave.channels 4;

ttable.0.0 1;

ttable.1.1 1;

ttable.2.2 1;

ttable.3.3 1;

}

ctl.ttable {

type hw;

card 0;

}

<--------------------------------------------------

and then get the Segmentation fault:

-------------------------------------------------------------->

[root@board /tmp]#./pb_pcm_min

open...ver:[0.71]

playback...capture...device=[multi_playback]

#####################snd_pcm_open...

zz[snd_dlsym_verify:122],vname=[_snd_config_hook_load_dlsym_config_hook_ 001]

zz[snd_dlsym_verify:127]

zz[snd_dlsym:167]

zz[snd_dlsym:171],name=[snd_config_hook_load]

zz[snd_pcm_open_conf:2163]

zz[snd_dlsym_verify:122],vname=[__snd_pcm_multi_open_dlsym_pcm_001]

Segmentation fault

[root@board /tmp]#

<---------------------------------------------------------------

To my surpris, it will be fine when run on the PC under the Ubuntu system.I used the same alsa-lib source code and the configure file asoundrc.

in my codec-driver .i have not call the functions :snd_soc_add_controls() / snd_soc_dapm_new_controls() / snd_soc_dapm_add_routes(). is it the reason? But the programm have not arrived here.

i have traced the source code when the Segmentation fault happened the alsa-lib was calling the function dlysm() with the param vname=__snd_pcm_multi_open_dlsym_pcm_001. But this will not happen on my PC under Ubuntu. could you help me find out what's wrong with me?

thanks a lot.

zw