Allocate virtual dma buffer
int snd_pcm_lib_alloc_vmalloc_buffer(struct snd_pcm_substream * substream, size_t size);
substream
the substream to allocate the buffer to
size
the requested buffer size, in bytes
Allocates the PCM substream buffer using vmalloc, i.e., the memory is contiguous in kernel virtual space, but not in physical memory. Use this if the buffer is accessed by kernel code but not by device DMA.
1 if the buffer was changed, 0 if not changed, or a negative error code.