ALSA: pcm: add tracepoints for final selection process of hardware parameters

Results of ioctl(2) with SNDRV_PCM_IOCTL_HW_REFINE and
SNDRV_PCM_IOCTL_HW_PARAMS are different, because the latter has single
value for several parameters; e.g. channels of PCM substream. Selection
of the single value is done independently of application of constraints.
It's helpful for developers to trace the selection process.

This commit adds tracepoints to snd_pcm_hw_params_choose() for the
purpose.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Takashi Sakamoto 2017-06-09 21:46:49 +09:00 committed by Takashi Iwai
parent 60f96aaecb
commit 7b8a54aff3

View File

@ -598,16 +598,38 @@ static int snd_pcm_hw_params_choose(struct snd_pcm_substream *pcm,
-1
};
const int *v;
struct snd_mask old_mask;
struct snd_interval old_interval;
int err;
for (v = vars; *v != -1; v++) {
/* Keep old parameter to trace. */
if (trace_hw_mask_param_enabled()) {
if (hw_is_mask(*v))
old_mask = *hw_param_mask(params, *v);
}
if (trace_hw_interval_param_enabled()) {
if (hw_is_interval(*v))
old_interval = *hw_param_interval(params, *v);
}
if (*v != SNDRV_PCM_HW_PARAM_BUFFER_SIZE)
err = snd_pcm_hw_param_first(pcm, params, *v, NULL);
else
err = snd_pcm_hw_param_last(pcm, params, *v, NULL);
if (snd_BUG_ON(err < 0))
return err;
/* Trace the parameter. */
if (hw_is_mask(*v)) {
trace_hw_mask_param(pcm, *v, 0, &old_mask,
hw_param_mask(params, *v));
}
if (hw_is_interval(*v)) {
trace_hw_interval_param(pcm, *v, 0, &old_interval,
hw_param_interval(params, *v));
}
}
return 0;
}