Unverified Commit 4065f0b2 authored by Martin Povišer's avatar Martin Povišer Committed by Mark Brown
Browse files

ASoC: apple: mca: Add locking 



In DAI ops, accesses to the native cluster (of the DAI), and to data of
clusters related to it by a DPCM frontend-backend link, should have
been synchronized by the 'pcm_mutex' lock at ASoC level.

What is not covered are the 'port_driver' accesses on foreign clusters
to which the current cluster has no a priori relation, so fill in
locking for that. (This should only matter in bizarre configurations of
sharing one MCA peripheral between ASoC cards.)

Signed-off-by: default avatarMartin Povišer <povik+lin@cutebit.org>
Link: https://lore.kernel.org/r/20220824160715.95779-5-povik+lin@cutebit.org


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 3df5d0d9

sound/soc/apple/mca.c

+21 −2
Original line number Diff line number Diff line
@@ -158,6 +158,9 @@ struct mca_data { 
	struct reset_control *rstc;

	struct device_link *pd_link;



	/* Mutex for accessing port_driver of foreign clusters */

	struct mutex port_mutex;



	int nclusters;

	struct mca_cluster clusters[];

};
@@ -296,16 +299,21 @@ static bool mca_fe_clocks_in_use(struct mca_cluster *cl) 
	struct mca_cluster *be_cl;

	int stream, i;



	mutex_lock(&mca->port_mutex);

	for (i = 0; i < mca->nclusters; i++) {

		be_cl = &mca->clusters[i];



		if (be_cl->port_driver != cl->no)

			continue;



		for_each_pcm_streams(stream)

			if (be_cl->clocks_in_use[stream])

		for_each_pcm_streams(stream) {

			if (be_cl->clocks_in_use[stream]) {

				mutex_unlock(&mca->port_mutex);

				return true;

			}

		}

	}

	mutex_unlock(&mca->port_mutex);

	return false;

}
@@ -349,6 +357,11 @@ static int mca_be_hw_free(struct snd_pcm_substream *substream, 
	if (cl->port_driver < 0)

		return -EINVAL;



	/*

	 * We are operating on a foreign cluster here, but since we

	 * belong to the same PCM, accesses should have been

	 * synchronized at ASoC level.

	 */

	fe_cl = &mca->clusters[cl->port_driver];

	if (!mca_fe_clocks_in_use(fe_cl))

		return 0; /* Nothing to do */
@@ -721,7 +734,9 @@ static int mca_be_startup(struct snd_pcm_substream *substream, 
		       cl->base + REG_PORT_CLOCK_SEL);

	writel_relaxed(PORT_DATA_SEL_TXA(fe_cl->no),

		       cl->base + REG_PORT_DATA_SEL);

	mutex_lock(&mca->port_mutex);

	cl->port_driver = fe_cl->no;

	mutex_unlock(&mca->port_mutex);

	cl->port_started[substream->stream] = true;



	return 0;
@@ -731,6 +746,7 @@ static void mca_be_shutdown(struct snd_pcm_substream *substream, 
			    struct snd_soc_dai *dai)

{

	struct mca_cluster *cl = mca_dai_to_cluster(dai);

	struct mca_data *mca = cl->host;



	cl->port_started[substream->stream] = false;
@@ -741,7 +757,9 @@ static void mca_be_shutdown(struct snd_pcm_substream *substream, 
		 */

		writel_relaxed(0, cl->base + REG_PORT_ENABLES);

		writel_relaxed(0, cl->base + REG_PORT_DATA_SEL);

		mutex_lock(&mca->port_mutex);

		cl->port_driver = -1;

		mutex_unlock(&mca->port_mutex);

	}

}
@@ -962,6 +980,7 @@ static int apple_mca_probe(struct platform_device *pdev) 
		return -ENOMEM;

	mca->dev = &pdev->dev;

	mca->nclusters = nclusters;

	mutex_init(&mca->port_mutex);

	platform_set_drvdata(pdev, mca);

	clusters = mca->clusters;