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

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Date:   Fri, 2 Aug 2019 22:58:43 +0530
From:   Vinod Koul <vkoul@...nel.org>
To:     Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>
Cc:     Cezary Rojewski <cezary.rojewski@...el.com>,
        alsa-devel@...a-project.org, linux-kernel@...r.kernel.org,
        tiwai@...e.de, broonie@...nel.org, gregkh@...uxfoundation.org,
        jank@...ence.com, srinivas.kandagatla@...aro.org,
        slawomir.blauciak@...el.com, Sanyog Kale <sanyog.r.kale@...el.com>
Subject: Re: [alsa-devel] [RFC PATCH 31/40] soundwire: intel: move shutdown()
 callback and don't export symbol

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,
> > > +            struct snd_soc_dai *dai)
> > > +{
> > > +    struct sdw_cdns_dma_data *dma;
> > > +
> > > +    dma = snd_soc_dai_get_dma_data(dai, substream);
> > > +    if (!dma)
> > > +        return;
> > > +
> > > +    snd_soc_dai_set_dma_data(dai, substream, NULL);
> > > +    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?

-- 
~Vinod