ALSA: pcm: add tracepoints for final selection process of hardware parameters (7b8a54af) · Commits · 戴 / test

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>

sound/core/pcm_native.c

+22 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

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