snd_pcm_lib_preallocate_pages

Langue: en

Autres versions - même langue

Version: June 2009 (debian - 07/07/09)

Section: 9 (Appels noyau Linux)

Sommaire

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 dependant 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.

Returns zero if successful, or a negative error code on failure.