forked from luck/tmp_suning_uos_patched
V4L/DVB (7494): videobuf-dma-sg.c: Avoid NULL dereference and add comment about backwards compatibility
Signed-off-by: Brandon Philips <bphilips@suse.de> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
parent
137d1cb19d
commit
ce54093cef
@ -546,6 +546,14 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
|
||||
goto done;
|
||||
}
|
||||
|
||||
/* This function maintains backwards compatibility with V4L1 and will
|
||||
* map more than one buffer if the vma length is equal to the combined
|
||||
* size of multiple buffers than it will map them together. See
|
||||
* VIDIOCGMBUF in the v4l spec
|
||||
*
|
||||
* TODO: Allow drivers to specify if they support this mode
|
||||
*/
|
||||
|
||||
/* look for first buffer to map */
|
||||
for (first = 0; first < VIDEO_MAX_FRAME; first++) {
|
||||
if (NULL == q->bufs[first])
|
||||
@ -590,10 +598,16 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
|
||||
map = kmalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
|
||||
if (NULL == map)
|
||||
goto done;
|
||||
for (size = 0, i = first; i <= last; size += q->bufs[i++]->bsize) {
|
||||
|
||||
size = 0;
|
||||
for (i = first; i <= last; i++) {
|
||||
if (NULL == q->bufs[i])
|
||||
continue;
|
||||
q->bufs[i]->map = map;
|
||||
q->bufs[i]->baddr = vma->vm_start + size;
|
||||
size += q->bufs[i]->bsize;
|
||||
}
|
||||
|
||||
map->count = 1;
|
||||
map->start = vma->vm_start;
|
||||
map->end = vma->vm_end;
|
||||
|
Loading…
Reference in New Issue
Block a user