V4L/DVB: dvb: fix smscore_getbuffer() logic
Drivers shouldn't sleep while holding a spinlock. A previous workaround
were to release the spinlock before callinc schedule().
This patch uses a different approach: it just waits for the
siano hardware to answer.
Signed-off-by: Richard Zidlicky <rz@linux-m68k.org>
Cc: stable@kernel.org
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/dvb/siano/smscoreapi.c b/drivers/media/dvb/siano/smscoreapi.c
index d93468c..ff3b0fa 100644
--- a/drivers/media/dvb/siano/smscoreapi.c
+++ b/drivers/media/dvb/siano/smscoreapi.c
@@ -1098,33 +1098,26 @@
*
* @return pointer to descriptor on success, NULL on error.
*/
-struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev)
+
+struct smscore_buffer_t *get_entry(struct smscore_device_t *coredev)
{
struct smscore_buffer_t *cb = NULL;
unsigned long flags;
- DEFINE_WAIT(wait);
-
spin_lock_irqsave(&coredev->bufferslock, flags);
-
- /* This function must return a valid buffer, since the buffer list is
- * finite, we check that there is an available buffer, if not, we wait
- * until such buffer become available.
- */
-
- prepare_to_wait(&coredev->buffer_mng_waitq, &wait, TASK_INTERRUPTIBLE);
- if (list_empty(&coredev->buffers)) {
- spin_unlock_irqrestore(&coredev->bufferslock, flags);
- schedule();
- spin_lock_irqsave(&coredev->bufferslock, flags);
+ if (!list_empty(&coredev->buffers)) {
+ cb = (struct smscore_buffer_t *) coredev->buffers.next;
+ list_del(&cb->entry);
}
-
- finish_wait(&coredev->buffer_mng_waitq, &wait);
-
- cb = (struct smscore_buffer_t *) coredev->buffers.next;
- list_del(&cb->entry);
-
spin_unlock_irqrestore(&coredev->bufferslock, flags);
+ return cb;
+}
+
+struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev)
+{
+ struct smscore_buffer_t *cb = NULL;
+
+ wait_event(coredev->buffer_mng_waitq, (cb = get_entry(coredev)));
return cb;
}
