CABLE_IS_40WIRE(9) libata Core Internals CABLE_IS_40WIRE(9)
NAME cable_is_40wire - 40/80/SATA decider
SYNOPSIS int cable_is_40wire(struct ata_port * ap);
ARGUMENTS ap port to consider
DESCRIPTION This function encapsulates the policy for speed management in one place. At the moment we don´t cache the result but there is a good case for setting ap->cbl to the result when we are called with unknown cables (and figuring out if it impacts hotplug at all).
Return 1 if the cable appears to be 40 wire.
AUTHOR Jeff Garzik Author.
COPYRIGHT Kernel Hackers Manual 2.6. July 2015 CABLE_IS_40WIRE(9)