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 struct- v4l2_buffer- lengthfield for the single-planar API and in the struct- v4l2_plane- lengthfield 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 - startor- lengthis incorrect, or no buffers have been mapped yet.