This reverts commit f514248727606b9087bc38a284ff686e0093abf1. The original patch attempted to acquire the card->controls_rwsem lock in fsl_xcvr_mode_put(). However, this function is called from the upper ALSA core function snd_ctl_elem_write(), which already holds the write lock on controls_rwsem for the whole put operation. So there is no need to simply hold the lock for fsl_xcvr_activate_ctl() again.
Acquiring the read lock while holding the write lock in the same thread results in a deadlock and a hung task, as reported by Alexander Stein. Reported-by: Alexander Stein <[email protected]> Closes: https://lore.kernel.org/linux-sound/5056506.GXAFRqVoOG@steina-w/ Signed-off-by: Ziyi Guo <[email protected]> --- sound/soc/fsl/fsl_xcvr.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/sound/soc/fsl/fsl_xcvr.c b/sound/soc/fsl/fsl_xcvr.c index 0b9dd64b9a82..a268fb81a2f8 100644 --- a/sound/soc/fsl/fsl_xcvr.c +++ b/sound/soc/fsl/fsl_xcvr.c @@ -223,13 +223,10 @@ static int fsl_xcvr_mode_put(struct snd_kcontrol *kcontrol, xcvr->mode = snd_soc_enum_item_to_val(e, item[0]); - down_read(&card->snd_card->controls_rwsem); fsl_xcvr_activate_ctl(dai, fsl_xcvr_arc_mode_kctl.name, (xcvr->mode == FSL_XCVR_MODE_ARC)); fsl_xcvr_activate_ctl(dai, fsl_xcvr_earc_capds_kctl.name, (xcvr->mode == FSL_XCVR_MODE_EARC)); - up_read(&card->snd_card->controls_rwsem); - /* Allow playback for SPDIF only */ rtd = snd_soc_get_pcm_runtime(card, card->dai_link); rtd->pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream_count = -- 2.34.1
