usb_ep_alloc_buffer(9)
NAME
usb_ep_alloc_buffer - allocate an I/O buffer
SYNOPSIS
void * usb_ep_alloc_buffer(struct usb_ep * ep, unsigned len, dma_addr_t * dma, gfp_t gfp_flags);
ARGUMENTS
- ep
- the endpoint associated with the buffer
- len
- length of the desired buffer
- dma
- pointer to the buffer's DMA address; must be valid
- gfp_flags
- GFP_* flags to use
DESCRIPTION
- Returns a new buffer, or null if one could not be allocat
- ed. The buffer is suitably aligned for dma, if that endpoint uses
- DMA, and the caller won't have to care about dma-inconsistency or
- any hidden "bounce buffer" mechanism. No additional per-request
- DMA mapping will be required for such buffers. Free it later with
- usb_ep_free_buffer.
- You don't need to use this call to allocate I/O buffers
- unless you want to make sure drivers don't incur costs for such
- "bounce buffer" copies or per-request DMA mappings.
AUTHOR
- David Brownell <dbrownell@users.sourceforge.net>
- Author.