The recent fix for DPCM locking also covered the loop in dpcm_be_disconnect() with the FE stream lock. This caused an unexpected side effect, thought: calling debugfs_remove_recursive() in the spinlock may lead to lockdep splats as the code there assumes the SOFTIRQ-safe context.
For avoiding the problem, this patch changes the disconnection procedure to two phases: at first, the matching entries are removed from the linked list, then the resources are freed outside the lock.
Fixes: b7898396f4bb ("ASoC: soc-pcm: Fix and cleanup DPCM locking") Reported-and-tested-by: Marek Szyprowski m.szyprowski@samsung.com Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/soc/soc-pcm.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c index e8876e65c649..9a954680d492 100644 --- a/sound/soc/soc-pcm.c +++ b/sound/soc/soc-pcm.c @@ -1268,6 +1268,7 @@ static void dpcm_be_reparent(struct snd_soc_pcm_runtime *fe, void dpcm_be_disconnect(struct snd_soc_pcm_runtime *fe, int stream) { struct snd_soc_dpcm *dpcm, *d; + LIST_HEAD(deleted_dpcms);
snd_soc_dpcm_mutex_assert_held(fe);
@@ -1287,13 +1288,18 @@ void dpcm_be_disconnect(struct snd_soc_pcm_runtime *fe, int stream) /* BEs still alive need new FE */ dpcm_be_reparent(fe, dpcm->be, stream);
- dpcm_remove_debugfs_state(dpcm); - list_del(&dpcm->list_be); + list_move(&dpcm->list_fe, &deleted_dpcms); + } + snd_soc_dpcm_stream_unlock_irq(fe, stream); + + while (!list_empty(&deleted_dpcms)) { + dpcm = list_first_entry(&deleted_dpcms, struct snd_soc_dpcm, + list_fe); list_del(&dpcm->list_fe); + dpcm_remove_debugfs_state(dpcm); kfree(dpcm); } - snd_soc_dpcm_stream_unlock_irq(fe, stream); }
/* get BE for DAI widget and stream */