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| author | Takashi Iwai <tiwai@suse.de> | 2008-08-11 12:18:39 +0400 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2008-10-20 16:47:15 +0400 |
| commit | 96c7d478efad594e483ee8a826395b1342404885 (patch) | |
| tree | 8ecb6f20f1f72f9d406b3c949d9b811347dcbb3e /sound/drivers/pcsp/pcsp.h | |
| parent | 76a4d10e522bfc238ddf70f35272088d420d2dcf (diff) | |
| download | linux-96c7d478efad594e483ee8a826395b1342404885.tar.xz | |
ALSA: pcsp - Fix locking messes in snd-pcsp
snd-pcsp driver takes chip->substream_lock together with PCM substream
lock. These are even mixed up with hrtimer's lock, resulting in messy
lock depencies. Right now, snd-pcsp driver resolves the deadlock by
using HRTIMER_CB_SOFTIRQ. However, this isn't nice for a really fast
path like bit-flipping.
This patch introduces a tasklet for PCM period handling so that the
hrtimer callback can be handled fast. This also reduce the use of
chip->substream_lock to avoid deadlocks. It's still used in pointer
callback, but even this could be removed with a proper barrier.
Another good solution is to introduce async trigger callback. But,
this will involve with a major rewrite of the PCM core code, so I
take first this easy fix.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/drivers/pcsp/pcsp.h')
| -rw-r--r-- | sound/drivers/pcsp/pcsp.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/sound/drivers/pcsp/pcsp.h b/sound/drivers/pcsp/pcsp.h index 1d661f795e8c..70533a333b5b 100644 --- a/sound/drivers/pcsp/pcsp.h +++ b/sound/drivers/pcsp/pcsp.h @@ -77,6 +77,7 @@ struct snd_pcsp { extern struct snd_pcsp pcsp_chip; extern enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle); +extern void pcsp_sync_stop(struct snd_pcsp *chip); extern int snd_pcsp_new_pcm(struct snd_pcsp *chip); extern int snd_pcsp_new_mixer(struct snd_pcsp *chip); |