[alsa-devel] ASoC: core: Call mute for cpu dais as well

[Babu, Ramesh]

> This is a semi-automatic email about new static checker warnings.
> 
> The patch ae11601b80b9: "ASoC: core: Call mute for cpu dais as well"
> from Oct 15, 2014, leads to the following Smatch complaint:
> 
> sound/soc/soc-pcm.c:777 soc_pcm_prepare()
> 	 error: we previously assumed 'cpu_dai->driver->ops' could be null
> (see line 755)
> 
> sound/soc/soc-pcm.c
>    754
>    755		if (cpu_dai->driver->ops && cpu_dai->driver->ops->prepare)
> {
>                     ^^^^^^^^^^^^^^^^^^^^ I don't think this can be NULL.  Probably
> we should remove this check.
Nope. ops can be NULL.

> 
>    756			ret = cpu_dai->driver->ops->prepare(substream,
> cpu_dai);
>    757			if (ret < 0) {
>    758				dev_err(cpu_dai->dev, "ASoC: DAI prepare
> error: %d\n",
>    759					ret);
>    760				goto out;
>    761			}
>    762		}
>    763
>    764		/* cancel any delayed stream shutdown that is pending */
>    765		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK
> &&
>    766		    rtd->pop_wait) {
>    767			rtd->pop_wait = 0;
>    768			cancel_delayed_work(&rtd->delayed_work);
>    769		}
>    770
>    771		snd_soc_dapm_stream_event(rtd, substream->stream,
>    772				SND_SOC_DAPM_STREAM_START);
>    773
>    774		for (i = 0; i < rtd->num_codecs; i++)
>    775			snd_soc_dai_digital_mute(rtd->codec_dais[i], 0,
>    776						 substream->stream);
>    777		snd_soc_dai_digital_mute(cpu_dai, 0, substream->stream);
>                                          ^^^^^^^ But if it were NULL then this newly introduced
> function call would Oops.
> 
I think the fix needs to be inside the snd_soc_dai_digital_mute().
Instead of checking dai->driver, it needs to check for dai->driver->ops.
It applies multple functions in soc-core.c.