From: Takashi Iwai <tiwai@xxxxxxx> commit 29bb274e94974669acb5186a75538f20df1508b6 upstream. The PCM core should perform the sync for the pending stop operations at disconnection. Otherwise it may lead to unexpected access. Currently the old user of sync_stop, USB-audio driver, has its own sync, so this isn't needed, but it's better to guarantee the sync in the PCM core level. This patch adds the missing sync_stop call at PCM disconnection callback. It also assures the IRQ sync if it's specified in the card. snd_pcm_sync_stop() is slightly modified to be called also for any PCM substream object now. Fixes: 1e850beea278 ("ALSA: pcm: Add the support for sync-stop operation") Cc: <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210206203656.15959-2-tiwai@xxxxxxx Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/core/init.c | 4 ++++ sound/core/pcm.c | 4 ++++ sound/core/pcm_local.h | 1 + sound/core/pcm_native.c | 16 ++++++++-------- 4 files changed, 17 insertions(+), 8 deletions(-) --- a/sound/core/init.c +++ b/sound/core/init.c @@ -14,6 +14,7 @@ #include <linux/ctype.h> #include <linux/pm.h> #include <linux/completion.h> +#include <linux/interrupt.h> #include <sound/core.h> #include <sound/control.h> @@ -418,6 +419,9 @@ int snd_card_disconnect(struct snd_card /* notify all devices that we are disconnected */ snd_device_disconnect_all(card); + if (card->sync_irq > 0) + synchronize_irq(card->sync_irq); + snd_info_card_disconnect(card); if (card->registered) { device_del(&card->card_dev); --- a/sound/core/pcm.c +++ b/sound/core/pcm.c @@ -1111,6 +1111,10 @@ static int snd_pcm_dev_disconnect(struct } } + for (cidx = 0; cidx < 2; cidx++) + for (substream = pcm->streams[cidx].substream; substream; substream = substream->next) + snd_pcm_sync_stop(substream, false); + pcm_call_notify(pcm, n_disconnect); for (cidx = 0; cidx < 2; cidx++) { snd_unregister_device(&pcm->streams[cidx].dev); --- a/sound/core/pcm_local.h +++ b/sound/core/pcm_local.h @@ -63,6 +63,7 @@ static inline void snd_pcm_timer_done(st void __snd_pcm_xrun(struct snd_pcm_substream *substream); void snd_pcm_group_init(struct snd_pcm_group *group); +void snd_pcm_sync_stop(struct snd_pcm_substream *substream, bool sync_irq); #ifdef CONFIG_SND_DMA_SGBUF struct page *snd_pcm_sgbuf_ops_page(struct snd_pcm_substream *substream, --- a/sound/core/pcm_native.c +++ b/sound/core/pcm_native.c @@ -583,13 +583,13 @@ static inline void snd_pcm_timer_notify( #endif } -static void snd_pcm_sync_stop(struct snd_pcm_substream *substream) +void snd_pcm_sync_stop(struct snd_pcm_substream *substream, bool sync_irq) { - if (substream->runtime->stop_operating) { + if (substream->runtime && substream->runtime->stop_operating) { substream->runtime->stop_operating = false; - if (substream->ops->sync_stop) + if (substream->ops && substream->ops->sync_stop) substream->ops->sync_stop(substream); - else if (substream->pcm->card->sync_irq > 0) + else if (sync_irq && substream->pcm->card->sync_irq > 0) synchronize_irq(substream->pcm->card->sync_irq); } } @@ -686,7 +686,7 @@ static int snd_pcm_hw_params(struct snd_ if (atomic_read(&substream->mmap_count)) return -EBADFD; - snd_pcm_sync_stop(substream); + snd_pcm_sync_stop(substream, true); params->rmask = ~0U; err = snd_pcm_hw_refine(substream, params); @@ -809,7 +809,7 @@ static int do_hw_free(struct snd_pcm_sub { int result = 0; - snd_pcm_sync_stop(substream); + snd_pcm_sync_stop(substream, true); if (substream->ops->hw_free) result = substream->ops->hw_free(substream); if (substream->managed_buffer_alloc) @@ -1736,7 +1736,7 @@ static void snd_pcm_post_resume(struct s snd_pcm_trigger_tstamp(substream); runtime->status->state = runtime->status->suspended_state; snd_pcm_timer_notify(substream, SNDRV_TIMER_EVENT_MRESUME); - snd_pcm_sync_stop(substream); + snd_pcm_sync_stop(substream, true); } static const struct action_ops snd_pcm_action_resume = { @@ -1866,7 +1866,7 @@ static int snd_pcm_do_prepare(struct snd snd_pcm_state_t state) { int err; - snd_pcm_sync_stop(substream); + snd_pcm_sync_stop(substream, true); err = substream->ops->prepare(substream); if (err < 0) return err;