Provided by:
linux-doc-2.6.15_2.6.15-23.39_all 
NAME
ata_choose_xfer_mode - attempt to find best transfer mode
SYNOPSIS
int ata_choose_xfer_mode (const struct ata_port * ap,
u8 * xfer_mode_out,
unsigned int * xfer_shift_out);
ARGUMENTS
ap Port for which an xfer mode will be selected
xfer_mode_out
(output) SET FEATURES - XFER MODE code
xfer_shift_out
(output) bit shift that selects this mode
DESCRIPTION
Based on host and device capabilities, determine the maximum transfer
mode that is amenable to all.
LOCKING
PCI/etc. bus probe sem.
RETURNS
Zero on success, negative on error.
AUTHOR
Jeff Garzik.