centos man page for snd_pcm_lib_preallocate_pages

SND_PCM_LIB_PREALLOC(9) 					      PCM API						   SND_PCM_LIB_PREALLOC(9)

NAME
       snd_pcm_lib_preallocate_pages - pre-allocation for the given DMA type

SYNOPSIS
       int snd_pcm_lib_preallocate_pages(struct snd_pcm_substream * substream, int type, struct device * data, size_t size, size_t max);

ARGUMENTS
       substream
	   the pcm substream instance

       type
	   DMA type (SNDRV_DMA_TYPE_*)

       data
	   DMA type dependent data

       size
	   the requested pre-allocation size in bytes

       max
	   the max. allowed pre-allocation size

DESCRIPTION
       Do pre-allocation for the given DMA buffer type.

       When substream->dma_buf_id is set, the function tries to look for the reserved buffer, and the buffer is not freed but reserved at
       destruction time. The dma_buf_id must be unique for all systems (in the same DMA buffer type) e.g. using snd_dma_pci_buf_id.

RETURN
       Zero if successful, or a negative error code on failure.

COPYRIGHT
Kernel Hackers Manual 3.10					     June 2014						   SND_PCM_LIB_PREALLOC(9)