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| author | Clemens Ladisch <clemens@ladisch.de> | 2012-05-13 19:07:22 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2012-05-14 10:43:43 +0200 |
| commit | 92b862c7d685f5971a954e6ded51891d4adc412b (patch) | |
| tree | 2843d2093df1ad58fac3274e67b208b2827546cd /sound | |
| parent | e9148dddc3c7b6121300319c3e31f9380d459be8 (diff) | |
| download | linux-3.10-92b862c7d685f5971a954e6ded51891d4adc412b.tar.gz linux-3.10-92b862c7d685f5971a954e6ded51891d4adc412b.tar.bz2 linux-3.10-92b862c7d685f5971a954e6ded51891d4adc412b.zip | |
ALSA: firewire-lib: optimize packet flushing
Trying to flush completed packets is pointless when the pointer
callback was called from the packet completion callback; avoid it.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound')
| -rw-r--r-- | sound/firewire/amdtp.c | 8 | ||||
| -rw-r--r-- | sound/firewire/amdtp.h | 1 |
2 files changed, 8 insertions, 1 deletions
diff --git a/sound/firewire/amdtp.c b/sound/firewire/amdtp.c index c2685fbd736..ea995af6d04 100644 --- a/sound/firewire/amdtp.c +++ b/sound/firewire/amdtp.c @@ -178,6 +178,7 @@ void amdtp_out_stream_pcm_prepare(struct amdtp_out_stream *s) tasklet_kill(&s->period_tasklet); s->pcm_buffer_pointer = 0; s->pcm_period_pointer = 0; + s->pointer_flush = true; } EXPORT_SYMBOL(amdtp_out_stream_pcm_prepare); @@ -393,6 +394,7 @@ static void queue_out_packet(struct amdtp_out_stream *s, unsigned int cycle) s->pcm_period_pointer += data_blocks; if (s->pcm_period_pointer >= pcm->runtime->period_size) { s->pcm_period_pointer -= pcm->runtime->period_size; + s->pointer_flush = false; tasklet_hi_schedule(&s->period_tasklet); } } @@ -539,7 +541,11 @@ EXPORT_SYMBOL(amdtp_out_stream_start); */ unsigned long amdtp_out_stream_pcm_pointer(struct amdtp_out_stream *s) { - fw_iso_context_flush_completions(s->context); + /* this optimization is allowed to be racy */ + if (s->pointer_flush) + fw_iso_context_flush_completions(s->context); + else + s->pointer_flush = true; return ACCESS_ONCE(s->pcm_buffer_pointer); } diff --git a/sound/firewire/amdtp.h b/sound/firewire/amdtp.h index 3f13ff63c5d..b680c5ef01d 100644 --- a/sound/firewire/amdtp.h +++ b/sound/firewire/amdtp.h @@ -68,6 +68,7 @@ struct amdtp_out_stream { unsigned int pcm_buffer_pointer; unsigned int pcm_period_pointer; + bool pointer_flush; }; int amdtp_out_stream_init(struct amdtp_out_stream *s, struct fw_unit *unit, |