7.68. V4L2 munmap()¶
7.68.1. Name¶
v4l2-munmap - Unmap device memory
7.68.2. Synopsis¶
#include <unistd.h>
#include <sys/mman.h>
-
int munmap(void *start, size_t length)¶
7.68.3. Arguments¶
start
Address of the mapped buffer as returned by the
mmap()
function.length
Length of the mapped buffer. This must be the same value as given to
mmap()
and returned by the driver in the structv4l2_buffer
length
field for the single-planar API and in the structv4l2_plane
length
field for the multi-planar API.
7.68.4. Description¶
Unmaps a previously with the mmap()
function mapped
buffer and frees it, if possible.
7.68.5. Return Value¶
On success munmap()
returns 0, on failure -1 and the
errno
variable is set appropriately:
- EINVAL
The
start
orlength
is incorrect, or no buffers have been mapped yet.