cable_is_40wire(9) centos man page | unix.com

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 3.10					     June 2014							CABLE_IS_40WIRE(9)