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| author | Takashi Iwai <tiwai@suse.de> | 2018-09-13 09:20:43 +0300 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2018-10-04 21:13:17 +0300 |
| commit | 6aea5702e27ebc85747d6e4943a0c378e1752be0 (patch) | |
| tree | c14ccb05935b7390997e8f4c74a5f4d4b2ab3617 /sound/core/rawmidi.c | |
| parent | cd3b7116b57527f659b96ff6988d2de3d448c5b3 (diff) | |
| download | linux-6aea5702e27ebc85747d6e4943a0c378e1752be0.tar.xz | |
ALSA: rawmidi: A lightweight function to discard pending bytes
For discarding the pending bytes on rawmidi, we process with a loop of
snd_rawmidi_transmit() which is just a waste of CPU power.
Implement a lightweight API function to discard the pending bytes and
the proceed the ring buffer instantly, and use it instead of open
codes.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core/rawmidi.c')
| -rw-r--r-- | sound/core/rawmidi.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/sound/core/rawmidi.c b/sound/core/rawmidi.c index 08d5662039e3..ee601d7f0926 100644 --- a/sound/core/rawmidi.c +++ b/sound/core/rawmidi.c @@ -1236,6 +1236,28 @@ int snd_rawmidi_transmit(struct snd_rawmidi_substream *substream, } EXPORT_SYMBOL(snd_rawmidi_transmit); +/** + * snd_rawmidi_proceed - Discard the all pending bytes and proceed + * @substream: rawmidi substream + * + * Return: the number of discarded bytes + */ +int snd_rawmidi_proceed(struct snd_rawmidi_substream *substream) +{ + struct snd_rawmidi_runtime *runtime = substream->runtime; + unsigned long flags; + int count = 0; + + spin_lock_irqsave(&runtime->lock, flags); + if (runtime->avail < runtime->buffer_size) { + count = runtime->buffer_size - runtime->avail; + __snd_rawmidi_transmit_ack(substream, count); + } + spin_unlock_irqrestore(&runtime->lock, flags); + return count; +} +EXPORT_SYMBOL(snd_rawmidi_proceed); + static long snd_rawmidi_kernel_write1(struct snd_rawmidi_substream *substream, const unsigned char __user *userbuf, const unsigned char *kernelbuf, |