| Message ID | 871rk4hean.wl-kuninori.morimoto.gx@renesas.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ASoC: soc-core: use client_mutex for snd_soc_find_dai() | expand |
Hi Mark > commit 25612477d20b52 ("ASoC: soc-dai: set dai_link dpcm_ flags with a helper") > added snd_soc_dai_link_set_capabilities(). > But it is using snd_soc_find_dai() (A) which is required client_mutex (B). > And client_mutex is soc-core.c local. > > struct snd_soc_dai *snd_soc_find_dai(xxx) > { > ... > (B) lockdep_assert_held(&client_mutex); > ... > } > > void snd_soc_dai_link_set_capabilities(xxx) > { > ... > for_each_pcm_streams(direction) { > ... > for_each_link_cpus(dai_link, i, cpu) { > (A) dai = snd_soc_find_dai(cpu); > ... > } > ... > for_each_link_codecs(dai_link, i, codec) { > (A) dai = snd_soc_find_dai(codec); > ... > } > } > ... > } > > Because of these background, we will get WARNING if .config has CONFIG_LOCKDEP. > > WARNING: CPU: 2 PID: 53 at sound/soc/soc-core.c:814 snd_soc_find_dai+0xf8/0x100 > CPU: 2 PID: 53 Comm: kworker/2:1 Not tainted 5.7.0-rc1+ #328 > Hardware name: Renesas H3ULCB Kingfisher board based on r8a77951 (DT) > Workqueue: events deferred_probe_work_func > pstate: 60000005 (nZCv daif -PAN -UAO) > pc : snd_soc_find_dai+0xf8/0x100 > lr : snd_soc_find_dai+0xf4/0x100 > ... > Call trace: > snd_soc_find_dai+0xf8/0x100 > snd_soc_dai_link_set_capabilities+0xa0/0x16c > graph_dai_link_of_dpcm+0x390/0x3c0 > graph_for_each_link+0x134/0x200 > graph_probe+0x144/0x230 > platform_drv_probe+0x5c/0xb0 > really_probe+0xe4/0x430 > driver_probe_device+0x60/0xf4 > > Many drivers are already calling snd_soc_find_dai() and/or snd_soc_dai_link_set_capabilities(). > Thus, same thing can be happen on these drivers, too. > > > grep snd_soc_find_dai -rl sound/soc/* > sound/soc/samsung/tm2_wm5110.c > sound/soc/soc-core.c > sound/soc/soc-dai.c > sound/soc/soc-topology.c > sound/soc/sof/topology.c > > > grep snd_soc_dai_link_set_capabilities -rl sound/soc/* > sound/soc/generic/simple-card.c > sound/soc/generic/audio-graph-card.c > sound/soc/qcom/common.c > sound/soc/soc-dai.c I noticed that samsung / sof are using snd_soc_find_dai() under client_mutex. This means this patch creates deadlock for these. Hmm... we need both _with_mutex() and _without_mutex(). Thank you for your help !! Best regards --- Kuninori Morimoto
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index fe23e936e2d1..6ea66b57b2c1 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -805,7 +805,7 @@ static struct snd_soc_component *soc_find_component( * * Return: pointer of DAI, or NULL if not found. */ -struct snd_soc_dai *snd_soc_find_dai( +static struct snd_soc_dai *snd_soc_find_dai_no_mutex( const struct snd_soc_dai_link_component *dlc) { struct snd_soc_component *component; @@ -829,6 +829,17 @@ struct snd_soc_dai *snd_soc_find_dai( return NULL; } + +struct snd_soc_dai *snd_soc_find_dai(const struct snd_soc_dai_link_component *dlc) +{ + struct snd_soc_dai *dai; + + mutex_lock(&client_mutex); + dai = snd_soc_find_dai_no_mutex(dlc); + mutex_unlock(&client_mutex); + + return dai; +} EXPORT_SYMBOL_GPL(snd_soc_find_dai); static int soc_dai_link_sanity_check(struct snd_soc_card *card, @@ -999,7 +1010,7 @@ int snd_soc_add_pcm_runtime(struct snd_soc_card *card, return -ENOMEM; for_each_link_cpus(dai_link, i, cpu) { - asoc_rtd_to_cpu(rtd, i) = snd_soc_find_dai(cpu); + asoc_rtd_to_cpu(rtd, i) = snd_soc_find_dai_no_mutex(cpu); if (!asoc_rtd_to_cpu(rtd, i)) { dev_info(card->dev, "ASoC: CPU DAI %s not registered\n", cpu->dai_name); @@ -1010,7 +1021,7 @@ int snd_soc_add_pcm_runtime(struct snd_soc_card *card, /* Find CODEC from registered CODECs */ for_each_link_codecs(dai_link, i, codec) { - asoc_rtd_to_codec(rtd, i) = snd_soc_find_dai(codec); + asoc_rtd_to_codec(rtd, i) = snd_soc_find_dai_no_mutex(codec); if (!asoc_rtd_to_codec(rtd, i)) { dev_info(card->dev, "ASoC: CODEC DAI %s not registered\n", codec->dai_name);