xhci: Use ilog2() rather than __ffs() for calculating SEGMENT_SHIFT

Use ilog2() rather than __ffs() for calculating SEGMENT_SHIFT as ilog2() can
be worked out at compile time, whereas __ffs() must be calculated at runtime.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: linux-usb@vger.kernel.org
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
This commit is contained in:
David Howells 2013-03-28 18:48:28 +00:00 committed by Sarah Sharp
parent 505bdbc79d
commit 6a5d6943fe

View File

@ -1239,7 +1239,7 @@ union xhci_trb {
/* Allow two commands + a link TRB, along with any reserved command TRBs */
#define MAX_RSVD_CMD_TRBS (TRBS_PER_SEGMENT - 3)
#define SEGMENT_SIZE (TRBS_PER_SEGMENT*16)
#define SEGMENT_SHIFT (__ffs(SEGMENT_SIZE))
#define SEGMENT_SHIFT (ilog2(SEGMENT_SIZE))
/* TRB buffer pointers can't cross 64KB boundaries */
#define TRB_MAX_BUFF_SHIFT 16
#define TRB_MAX_BUFF_SIZE (1 << TRB_MAX_BUFF_SHIFT)