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| author | Takashi Iwai <tiwai@suse.de> | 2018-09-13 08:20:43 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2018-10-04 20:13:17 +0200 |
| commit | 6aea5702e27ebc85747d6e4943a0c378e1752be0 (patch) | |
| tree | c14ccb05935b7390997e8f4c74a5f4d4b2ab3617 | |
| parent | ALSA: oxfw: use managed-resource to maintain cache of stream formats (diff) | |
| download | linux-6aea5702e27ebc85747d6e4943a0c378e1752be0.tar.xz linux-6aea5702e27ebc85747d6e4943a0c378e1752be0.zip | |
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>
| -rw-r--r-- | include/sound/rawmidi.h | 1 | ||||
| -rw-r--r-- | sound/core/rawmidi.c | 22 | ||||
| -rw-r--r-- | sound/core/seq/seq_virmidi.c | 4 | ||||
| -rw-r--r-- | sound/usb/midi.c | 3 |
4 files changed, 25 insertions, 5 deletions
diff --git a/include/sound/rawmidi.h b/include/sound/rawmidi.h index 6665cb29e1a2..3b5a061132b6 100644 --- a/include/sound/rawmidi.h +++ b/include/sound/rawmidi.h @@ -171,6 +171,7 @@ int __snd_rawmidi_transmit_peek(struct snd_rawmidi_substream *substream, unsigned char *buffer, int count); int __snd_rawmidi_transmit_ack(struct snd_rawmidi_substream *substream, int count); +int snd_rawmidi_proceed(struct snd_rawmidi_substream *substream); /* main midi functions */ 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, diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c index cb988efd1ed0..e5a40795914a 100644 --- a/sound/core/seq/seq_virmidi.c +++ b/sound/core/seq/seq_virmidi.c @@ -149,9 +149,7 @@ static void snd_vmidi_output_work(struct work_struct *work) /* discard the outputs in dispatch mode unless subscribed */ if (vmidi->seq_mode == SNDRV_VIRMIDI_SEQ_DISPATCH && !(vmidi->rdev->flags & SNDRV_VIRMIDI_SUBSCRIBE)) { - char buf[32]; - while (snd_rawmidi_transmit(substream, buf, sizeof(buf)) > 0) - ; /* ignored */ + snd_rawmidi_proceed(substream); return; } diff --git a/sound/usb/midi.c b/sound/usb/midi.c index dcfc546d81b9..b737f0ec77d0 100644 --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -1175,8 +1175,7 @@ static void snd_usbmidi_output_trigger(struct snd_rawmidi_substream *substream, if (port->ep->umidi->disconnected) { /* gobble up remaining bytes to prevent wait in * snd_rawmidi_drain_output */ - while (!snd_rawmidi_transmit_empty(substream)) - snd_rawmidi_transmit_ack(substream, 1); + snd_rawmidi_proceed(substream); return; } tasklet_schedule(&port->ep->tasklet); |