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path: root/sound/isa/msnd/msnd_midi.c
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Diffstat (limited to 'sound/isa/msnd/msnd_midi.c')
-rw-r--r--sound/isa/msnd/msnd_midi.c30
1 files changed, 15 insertions, 15 deletions
diff --git a/sound/isa/msnd/msnd_midi.c b/sound/isa/msnd/msnd_midi.c
index 912b5a9ccbab..013d8d1170fe 100644
--- a/sound/isa/msnd/msnd_midi.c
+++ b/sound/isa/msnd/msnd_midi.c
@@ -120,24 +120,24 @@ void snd_msndmidi_input_read(void *mpuv)
unsigned long flags;
struct snd_msndmidi *mpu = mpuv;
void *pwMIDQData = mpu->dev->mappedbase + MIDQ_DATA_BUFF;
+ u16 head, tail, size;
spin_lock_irqsave(&mpu->input_lock, flags);
- while (readw(mpu->dev->MIDQ + JQS_wTail) !=
- readw(mpu->dev->MIDQ + JQS_wHead)) {
- u16 wTmp, val;
- val = readw(pwMIDQData + 2 * readw(mpu->dev->MIDQ + JQS_wHead));
-
- if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER,
- &mpu->mode))
- snd_rawmidi_receive(mpu->substream_input,
- (unsigned char *)&val, 1);
-
- wTmp = readw(mpu->dev->MIDQ + JQS_wHead) + 1;
- if (wTmp > readw(mpu->dev->MIDQ + JQS_wSize))
- writew(0, mpu->dev->MIDQ + JQS_wHead);
- else
- writew(wTmp, mpu->dev->MIDQ + JQS_wHead);
+ head = readw(mpu->dev->MIDQ + JQS_wHead);
+ tail = readw(mpu->dev->MIDQ + JQS_wTail);
+ size = readw(mpu->dev->MIDQ + JQS_wSize);
+ if (head > size || tail > size)
+ goto out;
+ while (head != tail) {
+ unsigned char val = readw(pwMIDQData + 2 * head);
+
+ if (test_bit(MSNDMIDI_MODE_BIT_INPUT_TRIGGER, &mpu->mode))
+ snd_rawmidi_receive(mpu->substream_input, &val, 1);
+ if (++head > size)
+ head = 0;
+ writew(head, mpu->dev->MIDQ + JQS_wHead);
}
+ out:
spin_unlock_irqrestore(&mpu->input_lock, flags);
}
EXPORT_SYMBOL(snd_msndmidi_input_read);