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authorRichard Zidlicky <rz@linux-m68k.org>2010-08-24 09:52:36 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2010-09-27 22:21:59 -0300
commit3cdadc50bbe8f04c1231c8af614cafd7ddd622bf (patch)
treef42de4ed576985173c30d19befbe5570a6798948 /drivers/media
parent970d14c6cca8c71307a4d23fe373c5895175b2d7 (diff)
downloadblackbird-op-linux-3cdadc50bbe8f04c1231c8af614cafd7ddd622bf.tar.gz
blackbird-op-linux-3cdadc50bbe8f04c1231c8af614cafd7ddd622bf.zip
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>
Diffstat (limited to 'drivers/media')
-rw-r--r--drivers/media/dvb/siano/smscoreapi.c31
1 files changed, 12 insertions, 19 deletions
diff --git a/drivers/media/dvb/siano/smscoreapi.c b/drivers/media/dvb/siano/smscoreapi.c
index d93468cd3a85..ff3b0fa901b3 100644
--- a/drivers/media/dvb/siano/smscoreapi.c
+++ b/drivers/media/dvb/siano/smscoreapi.c
@@ -1098,33 +1098,26 @@ EXPORT_SYMBOL_GPL(smscore_onresponse);
*
* @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);
}
+ spin_unlock_irqrestore(&coredev->bufferslock, flags);
+ return cb;
+}
- finish_wait(&coredev->buffer_mng_waitq, &wait);
-
- cb = (struct smscore_buffer_t *) coredev->buffers.next;
- list_del(&cb->entry);
+struct smscore_buffer_t *smscore_getbuffer(struct smscore_device_t *coredev)
+{
+ struct smscore_buffer_t *cb = NULL;
- spin_unlock_irqrestore(&coredev->bufferslock, flags);
+ wait_event(coredev->buffer_mng_waitq, (cb = get_entry(coredev)));
return cb;
}
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