From bc518ba4ccb487ef52e418c3ff68050cf07b3bc0 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 23 Jan 2015 12:39:11 +0100 Subject: [PATCH] ALSA: line6: Reduce superfluous spinlock in midi.c The midi_transmit_lock is used always inside the send_urb_lock, thus it doesn't play any role. Let's kill it. Also, rename "send_urb_lock" as a more simple name "lock" since this is the only lock for midi. Tested-by: Chris Rorvick Signed-off-by: Takashi Iwai --- sound/usb/line6/midi.c | 18 ++++++------------ sound/usb/line6/midi.h | 7 +------ 2 files changed, 7 insertions(+), 18 deletions(-) diff --git a/sound/usb/line6/midi.c b/sound/usb/line6/midi.c index b5a58a7fe11a..beeedf9a2cbe 100644 --- a/sound/usb/line6/midi.c +++ b/sound/usb/line6/midi.c @@ -45,12 +45,9 @@ static void line6_midi_transmit(struct snd_rawmidi_substream *substream) line6_rawmidi_substream_midi(substream)->line6; struct snd_line6_midi *line6midi = line6->line6midi; struct midi_buffer *mb = &line6midi->midibuf_out; - unsigned long flags; unsigned char chunk[LINE6_FALLBACK_MAXPACKETSIZE]; int req, done; - spin_lock_irqsave(&line6->line6midi->midi_transmit_lock, flags); - for (;;) { req = min(line6_midibuf_bytes_free(mb), line6->max_packet_size); done = snd_rawmidi_transmit_peek(substream, chunk, req); @@ -71,8 +68,6 @@ static void line6_midi_transmit(struct snd_rawmidi_substream *substream) send_midi_async(line6, chunk, done); } - - spin_unlock_irqrestore(&line6->line6midi->midi_transmit_lock, flags); } /* @@ -92,7 +87,7 @@ static void midi_sent(struct urb *urb) if (status == -ESHUTDOWN) return; - spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags); + spin_lock_irqsave(&line6->line6midi->lock, flags); num = --line6->line6midi->num_active_send_urbs; if (num == 0) { @@ -103,12 +98,12 @@ static void midi_sent(struct urb *urb) if (num == 0) wake_up(&line6->line6midi->send_wait); - spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags); + spin_unlock_irqrestore(&line6->line6midi->lock, flags); } /* Send an asynchronous MIDI message. - Assumes that line6->line6midi->send_urb_lock is held + Assumes that line6->line6midi->lock is held (i.e., this function is serialized). */ static int send_midi_async(struct usb_line6 *line6, unsigned char *data, @@ -166,12 +161,12 @@ static void line6_midi_output_trigger(struct snd_rawmidi_substream *substream, line6_rawmidi_substream_midi(substream)->line6; line6->line6midi->substream_transmit = substream; - spin_lock_irqsave(&line6->line6midi->send_urb_lock, flags); + spin_lock_irqsave(&line6->line6midi->lock, flags); if (line6->line6midi->num_active_send_urbs == 0) line6_midi_transmit(substream); - spin_unlock_irqrestore(&line6->line6midi->send_urb_lock, flags); + spin_unlock_irqrestore(&line6->line6midi->lock, flags); } static void line6_midi_output_drain(struct snd_rawmidi_substream *substream) @@ -281,8 +276,7 @@ int line6_init_midi(struct usb_line6 *line6) rmidi->private_free = snd_line6_midi_free; init_waitqueue_head(&line6midi->send_wait); - spin_lock_init(&line6midi->send_urb_lock); - spin_lock_init(&line6midi->midi_transmit_lock); + spin_lock_init(&line6midi->lock); line6midi->line6 = line6; err = line6_midibuf_init(&line6midi->midibuf_in, MIDI_BUFFER_SIZE, 0); diff --git a/sound/usb/line6/midi.h b/sound/usb/line6/midi.h index ba6bf3828aa5..9d9467b2613c 100644 --- a/sound/usb/line6/midi.h +++ b/sound/usb/line6/midi.h @@ -39,15 +39,10 @@ struct snd_line6_midi { */ int num_active_send_urbs; - /** - Spin lock to protect updates of send_urb. - */ - spinlock_t send_urb_lock; - /** Spin lock to protect MIDI buffer handling. */ - spinlock_t midi_transmit_lock; + spinlock_t lock; /** Wait queue for MIDI transmission.