Man page 9 : snd_dma_get_reserved_buf

snd_dma_get_reserved_buf - get the reserved buffer for the given device

size_t snd_dma_get_reserved_buf(struct snd_dma_buffer *  dmab , unsigned int  id );

dmab
    the buffer allocation record to store

id
    the buffer id

Looks for the reserved-buffer list and re-uses if the same buffer is found in the list. When the buffer is found, itAqs removed from the free list.

The size of buffer if the buffer is found, or zero if not found.