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| author | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-04-13 12:08:55 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2008-04-13 12:08:55 -0300 |
| commit | c46748191d2f1175c2211b5ed20332935d06c9a8 (patch) | |
| tree | 6b05cdaefcc6fd21d4e3e0ab53e96a2bfe401e3d | |
| parent | 554dd58d9f1afff01a8d3e24d09f48e3e18566a1 (diff) | |
| download | mediapointer-dvb-s2-c46748191d2f1175c2211b5ed20332935d06c9a8.tar.gz mediapointer-dvb-s2-c46748191d2f1175c2211b5ed20332935d06c9a8.tar.bz2 | |
em28xx: Add missing checks
From: Mauro Carvalho Chehab <mchehab@infradead.org>
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>
| -rw-r--r-- | linux/drivers/media/video/em28xx/em28xx-video.c | 37 |
1 files changed, 25 insertions, 12 deletions
diff --git a/linux/drivers/media/video/em28xx/em28xx-video.c b/linux/drivers/media/video/em28xx/em28xx-video.c index 53e460cf9..0d8b359d1 100644 --- a/linux/drivers/media/video/em28xx/em28xx-video.c +++ b/linux/drivers/media/video/em28xx/em28xx-video.c @@ -290,24 +290,40 @@ 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); -#if 0 +#if 1 char *outp; #endif - /* 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); - -#if 0 - /* Cleans up buffer - Usefull for testing for frame continuity */ +#if 1 + /* Cleans up buffer - Usefull for testing for frame/URB loss */ outp = videobuf_to_vmalloc(&(*buf)->vb); memset(outp, 0, (*buf)->vb.size); #endif @@ -419,12 +435,11 @@ 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++) { @@ -438,8 +453,6 @@ static void em28xx_irq_callback(struct urb *urb) em28xx_err("urb resubmit failed (error=%i)\n", urb->status); } - - spin_unlock_irqrestore(&dev->slock, flags); } /* |