On Fri, 3 Aug 2007 11:20:49 -0700
stan <stanl@xxxxxxx> wrote:
> Fedora 7 upgraded alsa to 1.0.14 from RC3. I was going to test the
> default device sound for my prior problem (as requested by Takashi
> weeks ago). Unfortunately when I try to run my app it won't start.
> The snd_pcm_hw_params_set_format fails when I try to use it as
> follows.
>
> err = snd_pcm_hw_params_set_access (alsa_dev, hw_params,
> ND_PCM_ACCESS_RW_INTERLEAVED); if (err < 0)
> { fprintf (stderr, "cannot set access type (%s)\n",
> snd_strerror (err)) ; goto catch_error ;
> } ;
>
> err = snd_pcm_hw_params_set_format (alsa_dev, hw_params,
> SND_PCM_FORMAT_FLOAT64_LE); //err = snd_pcm_hw_params_set_format
> (alsa_dev, hw_params, SND_PCM_FORMAT_S32_LE); if (err < 0)
> { fprintf (stderr, "cannot set sample format (%s)\n",
> snd_strerror (err)) ; goto catch_error ;
> } ;
>
>
> cannot set sample format (Invalid argument)
>
> It compiles cleanly. When I replace the SND_PCM_FORMAT_FLOAT64_LE
> with the S32_LE, it sets it, but of course the sound is garbage
> as it is still receiving doubles.
>
> This code worked fine under RC3.
> Is there some change that occurred in the step from 1.0.14.rc3 to
> 1.0.14 that would explain the above and suggest a fix?
Used gdb to look at what was happening here. It seems to succeed in
the alsa lib but a return value gets translated from 1 to -22.
int _snd_pcm_hw_param_set(snd_pcm_hw_params_t *params,
snd_pcm_hw_param_t var, unsigned int val, int dir) {
int changed;
if (hw_is_mask(var)) {
snd_mask_t *m = hw_param_mask(params, var);
if (val == 0 && dir < 0) {
changed = -EINVAL;
snd_mask_none(m);
} else {
if (dir > 0)
val++;
else if (dir < 0)
val--;
changed =
snd_mask_refine_set(hw_param_mask(params, var), val); } <-- returns 1, change occurred
...
if (changed) { <-- this branch is taken
params->cmask |= 1 << var;
params->rmask |= 1 << var;
}
return changed; <-- changed is still 1 at this point
}
In the function below, which calls the function above, gdb tells me the
return value, err, has been
optimized away when I try to check it. When I check the return value
in the calling program for the function below it is -22.
int snd_pcm_hw_param_set(snd_pcm_t *pcm, snd_pcm_hw_params_t *params,
snd_set_mode_t mode,
snd_pcm_hw_param_t var, unsigned int val, int dir) {
snd_pcm_hw_params_t save;
int err;
switch (mode) {
case SND_CHANGE:
break;
case SND_TRY:
save = *params; <-- takes this branch
break;
case SND_TEST:
save = *params;
params = &save;
break;
default:
assert(0);
return -EINVAL;
}
err is optimized away in the code below, but must be less than zero
as it takes the _fail branch. The return value from the function above
is 1 so it shouldn't be taking the fail branch.
err = _snd_pcm_hw_param_set(params, var, val, dir);
if (err < 0)
goto _fail;
When I ignore the return value in my program from within gdb, everything runs,
but the sound is incorrect (static). And I get a garbage value back.
Format (3157552) <-- actual value set by alsa-lib
Format (3157552) differs from requested (16) <-- this is SND_PCM_FORMAT_FLOAT64
When I ignore the return value in my program with optimization (O2) turned on,
everything runs but the sound is incorrect (static).
The value that comes back is different though.
Format (0) <-- actual value set by alsa-lib
Format (0) differs from requested (16) <-- this is SND_PCM_FORMAT_FLOAT64
I find it hard to believe that this is a compiler optimization error.
It seems like the stack is becoming corrupted for just one call. All
other calls succeed.
Has anyone a suggestion of where the error might be or a possible workaround?
Could invalid values in the ICE1724 driver cause this?
>
> Thank you.
>
> $ uname -r
> 2.6.22.1-41.fc7
>
> $ cat /proc/asound/version
> Advanced Linux Sound Architecture Driver Version 1.0.14 (Thu May 31
> 09:03:25 2007 UTC).
>
> $ ls /proc/asound/card0
> ice1724 id oss_mixer pcm0c pcm0p pcm1p pcm2p
>
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
