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 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.