Re: [alsa-devel] [RFC PATCH 31/40] soundwire: intel: move shutdown() callback and don't export symbol

[Pierre-Louis Bossart]

On 8/2/19 12:28 PM, Vinod Koul wrote:
> On 26-07-19, 09:46, Pierre-Louis Bossart wrote:
> > On 7/26/19 5:38 AM, Cezary Rojewski wrote:
> > > On 2019-07-26 01:40, Pierre-Louis Bossart wrote:
> > > > +void intel_shutdown(struct snd_pcm_substream *substream,
> > > > +ÂÂÂÂÂÂÂÂÂÂÂ struct snd_soc_dai *dai)
> > > > +{
> > > > +ÂÂÂ struct sdw_cdns_dma_data *dma;
> > > > +
> > > > +ÂÂÂ dma = snd_soc_dai_get_dma_data(dai, substream);
> > > > +ÂÂÂ if (!dma)
> > > > +ÂÂÂÂÂÂÂ return;
> > > > +
> > > > +ÂÂÂ snd_soc_dai_set_dma_data(dai, substream, NULL);
> > > > +ÂÂÂ kfree(dma);
> > > > +}
> > >
> > > Correct me if I'm wrong, but do we really need to _get_dma_ here?
> > > _set_dma_ seems bulletproof, same for kfree.
> >
> > I must admit I have no idea why we have a reference to DMAs here, this looks
> > like an abuse to store a dai-specific context, and the initial test looks
> > like copy-paste to detect invalid configs, as done in other callbacks. Vinod
> > and Sanyog might have more history than me here.
>
> I dont see snd_soc_dai_set_dma_data() call for
> sdw_cdns_dma_data so somthing is missing (at least in upstream code)
>
> IIRC we should have a snd_soc_dai_set_dma_data() in alloc or some
> initialization routine and we free it here.. Sanyog?

the code does a bunch of get_dma_data() and this seems to work, but 
indeed I don't see where the _set_dma_data() is done. magic.