Signed-off-by: Andrej Krutak dev@andree.sk --- sound/usb/line6/driver.c | 16 +++++++++++----- sound/usb/line6/driver.h | 3 ++- 2 files changed, 13 insertions(+), 6 deletions(-)
diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c index 0a0e324..344465f 100644 --- a/sound/usb/line6/driver.c +++ b/sound/usb/line6/driver.c @@ -541,8 +541,7 @@ static int line6_hwdep_open(struct snd_hwdep *hw, struct file *file) line6->buffer_circular.head = 0; line6->buffer_circular.tail = 0; sema_init(&line6->buffer_circular.sem, 0); - - line6->buffer_circular.active = 1; + spin_lock_init(&line6->buffer_circular.read_lock);
line6->buffer_circular.data = kmalloc(LINE6_MESSAGE_MAXLEN * LINE6_MESSAGE_MAXCOUNT, GFP_KERNEL); @@ -567,7 +566,7 @@ static int line6_hwdep_release(struct snd_hwdep *hw, struct file *file)
/* By this time, no readers are waiting, we can safely recreate the * semaphore at next open. */ - line6->buffer_circular.active = 0; + clear_bit(0, &line6->buffer_circular.active);
kfree(line6->buffer_circular.data); kfree(line6->buffer_circular.data_len); @@ -581,18 +580,23 @@ line6_hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, { struct usb_line6 *line6 = hwdep->private_data; unsigned long tail; + long rv = 0;
if (down_interruptible(&line6->buffer_circular.sem)) { return -ERESTARTSYS; } /* There must an item now in the buffer... */
+ spin_lock(&line6->buffer_circular.read_lock); + tail = line6->buffer_circular.tail;
if (line6->buffer_circular.data_len[tail] > count) { /* Buffer too small; allow re-read of the current item... */ up(&line6->buffer_circular.sem); - return -EINVAL; + + rv = -EINVAL; + goto end; }
if (copy_to_user(buf, @@ -608,7 +612,9 @@ line6_hwdep_read(struct snd_hwdep *hwdep, char __user *buf, long count, smp_store_release(&line6->buffer_circular.tail, (tail + 1) & (LINE6_MESSAGE_MAXCOUNT - 1));
- return 0; +end: + spin_unlock(&line6->buffer_circular.read_lock); + return rv; }
/* Write directly (no buffering) to device by user*/ diff --git a/sound/usb/line6/driver.h b/sound/usb/line6/driver.h index f4ab6cd..05e155c 100644 --- a/sound/usb/line6/driver.h +++ b/sound/usb/line6/driver.h @@ -159,12 +159,13 @@ struct usb_line6 {
/* Circular buffer for non-MIDI control messages */ struct { - int active; + unsigned long active; char *data; int *data_len; unsigned long head, tail; /* Actually is up'd # of items in the buffer - times */ struct semaphore sem; + spinlock_t read_lock; } buffer_circular;
/* If MIDI is supported, buffer_message contains the pre-processed data;