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 --- include/sound/rawmidi.h | 1 + sound/core/rawmidi.c | 22 ++++++++++++++++++++++ sound/core/seq/seq_virmidi.c | 4 +--- 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);