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| author | Takashi Iwai <tiwai@suse.de> | 2018-07-30 14:48:29 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2018-07-30 14:52:30 +0200 |
| commit | 89b4ab213feb11a5bece544cfa12374f66c2c47c (patch) | |
| tree | 9a1725a0138dc002d2c65481cf96e5f8eb0e2e57 /sound/core | |
| parent | ALSA: seq: virmidi: Offload the output event processing (diff) | |
| download | linux-89b4ab213feb11a5bece544cfa12374f66c2c47c.tar.xz linux-89b4ab213feb11a5bece544cfa12374f66c2c47c.zip | |
ALSA: seq: virmidi: Use READ_ONCE/WRITE_ONCE() macros
The trigger flag in vmidi object can be referred in different contexts
concurrently, hence it's better to be put with READ_ONCE() and
WRITE_ONCE() macros to assure the accesses.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
| -rw-r--r-- | sound/core/seq/seq_virmidi.c | 14 |
1 files changed, 5 insertions, 9 deletions
diff --git a/sound/core/seq/seq_virmidi.c b/sound/core/seq/seq_virmidi.c index 67ea5d62cebc..03ac5e72dbe6 100644 --- a/sound/core/seq/seq_virmidi.c +++ b/sound/core/seq/seq_virmidi.c @@ -89,7 +89,7 @@ static int snd_virmidi_dev_receive_event(struct snd_virmidi_dev *rdev, else down_read(&rdev->filelist_sem); list_for_each_entry(vmidi, &rdev->filelist, list) { - if (!vmidi->trigger) + if (!READ_ONCE(vmidi->trigger)) continue; if (ev->type == SNDRV_SEQ_EVENT_SYSEX) { if ((ev->flags & SNDRV_SEQ_EVENT_LENGTH_MASK) != SNDRV_SEQ_EVENT_LENGTH_VARIABLE) @@ -147,11 +147,7 @@ static void snd_virmidi_input_trigger(struct snd_rawmidi_substream *substream, i { struct snd_virmidi *vmidi = substream->runtime->private_data; - if (up) { - vmidi->trigger = 1; - } else { - vmidi->trigger = 0; - } + WRITE_ONCE(vmidi->trigger, !!up); } /* process rawmidi bytes and send events; @@ -175,7 +171,7 @@ static void snd_vmidi_output_work(struct work_struct *work) return; } - while (vmidi->trigger) { + while (READ_ONCE(vmidi->trigger)) { if (snd_rawmidi_transmit(substream, &input, 1) != 1) break; if (snd_midi_event_encode_byte(vmidi->parser, input, @@ -201,7 +197,7 @@ static void snd_virmidi_output_trigger(struct snd_rawmidi_substream *substream, { struct snd_virmidi *vmidi = substream->runtime->private_data; - vmidi->trigger = !!up; + WRITE_ONCE(vmidi->trigger, !!up); if (up) queue_work(system_highpri_wq, &vmidi->output_work); } @@ -289,7 +285,7 @@ static int snd_virmidi_output_close(struct snd_rawmidi_substream *substream) { struct snd_virmidi *vmidi = substream->runtime->private_data; - vmidi->trigger = 0; /* to be sure */ + WRITE_ONCE(vmidi->trigger, false); /* to be sure */ cancel_work_sync(&vmidi->output_work); snd_midi_event_free(vmidi->parser); substream->runtime->private_data = NULL; |