aboutsummaryrefslogtreecommitdiff
path: root/drivers
diff options
context:
space:
mode:
authorMauro Carvalho Chehab <mchehab@infradead.org>2008-04-13 15:08:55 -0300
committerMauro Carvalho Chehab <mchehab@infradead.org>2008-04-24 14:09:39 -0300
commitdbecb44c11d9517d604240b53581951ac4e3b5e6 (patch)
tree3bf65736b1ae105e16227110452aa72d2dc21847 /drivers
parent0cf4daee31d88086cf3508d1d8d1f4e451c27906 (diff)
V4L/DVB (7563): em28xx: Add missing checks
There are some cases where nobody is waiting for a buffer. Due to the lack of check, if you try to abort the userspace app, machine were hanging, since IRQ were trying to use a buffer that were disallocated. Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/media/video/em28xx/em28xx-video.c35
1 files changed, 26 insertions, 9 deletions
diff --git a/drivers/media/video/em28xx/em28xx-video.c b/drivers/media/video/em28xx/em28xx-video.c
index db3bbacb3a7..10928dccaec 100644
--- a/drivers/media/video/em28xx/em28xx-video.c
+++ b/drivers/media/video/em28xx/em28xx-video.c
@@ -270,19 +270,39 @@ static inline int get_next_buf(struct em28xx_dmaqueue *dma_q,
struct em28xx_buffer **buf)
{
struct em28xx *dev = container_of(dma_q, struct em28xx, vidq);
+ char *outp;
- /* If the previous buffer were not filled yet, continue */
+ if (list_empty(&dma_q->active)) {
+ em28xx_isocdbg("No active queue to serve\n");
+ dev->isoc_ctl.buf = NULL;
+ return 0;
+ }
+
+ /* Check if the last buffer were fully filled */
*buf = dev->isoc_ctl.buf;
+
+ /* Nobody is waiting on this buffer - discards */
+ if (*buf && !waitqueue_active(&(*buf)->vb.done)) {
+ dev->isoc_ctl.buf = NULL;
+ *buf = NULL;
+ }
+
+ /* Returns the last buffer, to be filled with remaining data */
if (*buf)
return 1;
- if (list_empty(&dma_q->active)) {
+ /* Get the next buffer */
+ *buf = list_entry(dma_q->active.next, struct em28xx_buffer, vb.queue);
+
+ /* Nobody is waiting on the next buffer. returns */
+ if (!*buf || !waitqueue_active(&(*buf)->vb.done)) {
em28xx_isocdbg("No active queue to serve\n");
return 0;
}
- *buf = list_entry(dma_q->active.next, struct em28xx_buffer, vb.queue);
-
+ /* Cleans up buffer - Usefull for testing for frame/URB loss */
+ outp = videobuf_to_vmalloc(&(*buf)->vb);
+ memset(outp, 0, (*buf)->vb.size);
dev->isoc_ctl.buf = *buf;
@@ -387,12 +407,11 @@ static void em28xx_irq_callback(struct urb *urb)
struct em28xx_dmaqueue *dma_q = urb->context;
struct em28xx *dev = container_of(dma_q, struct em28xx, vidq);
int rc, i;
- unsigned long flags;
-
- spin_lock_irqsave(&dev->slock, flags);
/* Copy data from URB */
+ spin_lock(&dev->slock);
rc = em28xx_isoc_copy(urb);
+ spin_unlock(&dev->slock);
/* Reset urb buffers */
for (i = 0; i < urb->number_of_packets; i++) {
@@ -406,8 +425,6 @@ static void em28xx_irq_callback(struct urb *urb)
em28xx_err("urb resubmit failed (error=%i)\n",
urb->status);
}
-
- spin_unlock_irqrestore(&dev->slock, flags);
}
/*