From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753713Ab3C1Ssd (ORCPT ); Thu, 28 Mar 2013 14:48:33 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8581 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751493Ab3C1Ssb (ORCPT ); Thu, 28 Mar 2013 14:48:31 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 Subject: [PATCH 1/2] xhci: Use ilog2() rather than __ffs() for calculating SEGMENT_SHIFT To: sarah.a.sharp@linux.intel.com From: David Howells Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Date: Thu, 28 Mar 2013 18:48:28 +0000 Message-ID: <20130328184827.29679.62426.stgit@warthog.procyon.org.uk> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 cc: Sarah Sharp cc: Greg Kroah-Hartman cc: linux-usb@vger.kernel.org --- drivers/usb/host/xhci.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 2c510e4..558ba50 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1235,7 +1235,7 @@ 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)