diff options
author | Takashi Iwai <tiwai@suse.de> | 2018-01-15 16:48:36 +0100 |
---|---|---|
committer | Takashi Iwai <tiwai@suse.de> | 2018-01-15 16:48:36 +0100 |
commit | 671ec859e5ee06ab0bf968e639a25576b18865ad (patch) | |
tree | 43385603e1e54f05587ec7f6fe0eb63bba9498a9 /sound/core/seq/seq_timer.c | |
parent | 4ea5553a51e55664f86bed29e62e67ecb45bedd8 (diff) |
ALSA: seq: Process queue tempo/ppq change in a shot
The SNDRV_SEQ_IOCTL_SET_QUEUE_TEMPO ioctl sets the tempo and the ppq
in a single call, while the current implementation updates each value
one by one. This is a bit racy, and also suboptimal from the
performance POV, as each call does re-acquire the lock and invokes
the update of ALSA timer resolution.
This patch reorganizes the code slightly so that we change both the
tempo and the ppq in a shot. The skew value can be put into the same
lock, but this is rather a rarely used feature and completely
independent from the temp/ppq (it's evaluated only in the interrupt),
so it's left as it was.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/seq/seq_timer.c')
-rw-r--r-- | sound/core/seq/seq_timer.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/sound/core/seq/seq_timer.c b/sound/core/seq/seq_timer.c index b80985fbc334..23167578231f 100644 --- a/sound/core/seq/seq_timer.c +++ b/sound/core/seq/seq_timer.c @@ -191,14 +191,15 @@ int snd_seq_timer_set_tempo(struct snd_seq_timer * tmr, int tempo) return 0; } -/* set current ppq */ -int snd_seq_timer_set_ppq(struct snd_seq_timer * tmr, int ppq) +/* set current tempo and ppq in a shot */ +int snd_seq_timer_set_tempo_ppq(struct snd_seq_timer *tmr, int tempo, int ppq) { + int changed; unsigned long flags; if (snd_BUG_ON(!tmr)) return -EINVAL; - if (ppq <= 0) + if (tempo <= 0 || ppq <= 0) return -EINVAL; spin_lock_irqsave(&tmr->lock, flags); if (tmr->running && (ppq != tmr->ppq)) { @@ -208,9 +209,11 @@ int snd_seq_timer_set_ppq(struct snd_seq_timer * tmr, int ppq) pr_debug("ALSA: seq: cannot change ppq of a running timer\n"); return -EBUSY; } - + changed = (tempo != tmr->tempo) || (ppq != tmr->ppq); + tmr->tempo = tempo; tmr->ppq = ppq; - snd_seq_timer_set_tick_resolution(tmr); + if (changed) + snd_seq_timer_set_tick_resolution(tmr); spin_unlock_irqrestore(&tmr->lock, flags); return 0; } |