From 06f08e3a4d86e746f5e8e09030e6560e37386b7f Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Sat, 9 Oct 2010 21:15:33 -0300 Subject: [PATCH] [media] tm6000-alsa: fix some locking issues Those locking issues affect tvtime, causing a kernel oops/panic, due to a race condition. Signed-off-by: Mauro Carvalho Chehab --- drivers/staging/tm6000/tm6000-alsa.c | 46 ++++++++++++++++++++++------ drivers/staging/tm6000/tm6000.h | 3 ++ 2 files changed, 40 insertions(+), 9 deletions(-) diff --git a/drivers/staging/tm6000/tm6000-alsa.c b/drivers/staging/tm6000/tm6000-alsa.c index a99101fef1a3..e379e3ec4442 100644 --- a/drivers/staging/tm6000/tm6000-alsa.c +++ b/drivers/staging/tm6000/tm6000-alsa.c @@ -201,6 +201,14 @@ _error: */ static int snd_tm6000_close(struct snd_pcm_substream *substream) { + struct snd_tm6000_card *chip = snd_pcm_substream_chip(substream); + struct tm6000_core *core = chip->core; + + if (atomic_read(&core->stream_started) > 0) { + atomic_set(&core->stream_started, 0); + schedule_work(&core->wq_trigger); + } + return 0; } @@ -213,6 +221,9 @@ static int tm6000_fillbuf(struct tm6000_core *core, char *buf, int size) unsigned int stride, buf_pos; int length; + if (atomic_read(&core->stream_started) == 0) + return 0; + if (!size || !substream) { dprintk(1, "substream was NULL\n"); return -EINVAL; @@ -298,8 +309,12 @@ static int snd_tm6000_hw_params(struct snd_pcm_substream *substream, static int snd_tm6000_hw_free(struct snd_pcm_substream *substream) { struct snd_tm6000_card *chip = snd_pcm_substream_chip(substream); + struct tm6000_core *core = chip->core; - _tm6000_stop_audio_dma(chip); + if (atomic_read(&core->stream_started) > 0) { + atomic_set(&core->stream_started, 0); + schedule_work(&core->wq_trigger); + } return 0; } @@ -321,30 +336,42 @@ static int snd_tm6000_prepare(struct snd_pcm_substream *substream) /* * trigger callback */ +static void audio_trigger(struct work_struct *work) +{ + struct tm6000_core *core = container_of(work, struct tm6000_core, + wq_trigger); + struct snd_tm6000_card *chip = core->adev; + + if (atomic_read(&core->stream_started)) { + dprintk(1, "starting capture"); + _tm6000_start_audio_dma(chip); + } else { + dprintk(1, "stopping capture"); + _tm6000_stop_audio_dma(chip); + } +} + static int snd_tm6000_card_trigger(struct snd_pcm_substream *substream, int cmd) { struct snd_tm6000_card *chip = snd_pcm_substream_chip(substream); - int err; - - spin_lock(&chip->reg_lock); + struct tm6000_core *core = chip->core; + int err = 0; switch (cmd) { case SNDRV_PCM_TRIGGER_START: - err = _tm6000_start_audio_dma(chip); + atomic_set(&core->stream_started, 1); break; case SNDRV_PCM_TRIGGER_STOP: - err = _tm6000_stop_audio_dma(chip); + atomic_set(&core->stream_started, 0); break; default: err = -EINVAL; break; } - - spin_unlock(&chip->reg_lock); + schedule_work(&core->wq_trigger); return err; } - /* * pointer callback */ @@ -437,6 +464,7 @@ int tm6000_audio_init(struct tm6000_core *dev) snd_pcm_set_ops(pcm, SNDRV_PCM_STREAM_CAPTURE, &snd_tm6000_pcm_ops); + INIT_WORK(&dev->wq_trigger, audio_trigger); rc = snd_card_register(card); if (rc < 0) goto error; diff --git a/drivers/staging/tm6000/tm6000.h b/drivers/staging/tm6000/tm6000.h index 1ec1bff9b294..5d9dcab5c87d 100644 --- a/drivers/staging/tm6000/tm6000.h +++ b/drivers/staging/tm6000/tm6000.h @@ -205,6 +205,9 @@ struct tm6000_core { /* audio support */ struct snd_tm6000_card *adev; + struct work_struct wq_trigger; /* Trigger to start/stop audio for alsa module */ + atomic_t stream_started; /* stream should be running if true */ + struct tm6000_IR *ir; -- 2.39.5