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: Martin Povišer povik+lin@cutebit.org --- sound/soc/apple/mca.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/sound/soc/apple/mca.c b/sound/soc/apple/mca.c index 807b85469408..aa67d57c9a9b 100644 --- a/sound/soc/apple/mca.c +++ b/sound/soc/apple/mca.c @@ -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;