From owner-svn-src-head@FreeBSD.ORG  Mon Jan 24 17:38:38 2011
Return-Path: <owner-svn-src-head@FreeBSD.ORG>
Delivered-To: svn-src-head@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id 3C87D106564A;
	Mon, 24 Jan 2011 17:38:38 +0000 (UTC)
	(envelope-from hselasky@FreeBSD.org)
Received: from svn.freebsd.org (svn.freebsd.org [IPv6:2001:4f8:fff6::2c])
	by mx1.freebsd.org (Postfix) with ESMTP id 2BB068FC0A;
	Mon, 24 Jan 2011 17:38:38 +0000 (UTC)
Received: from svn.freebsd.org (localhost [127.0.0.1])
	by svn.freebsd.org (8.14.3/8.14.3) with ESMTP id p0OHccM6000527;
	Mon, 24 Jan 2011 17:38:38 GMT
	(envelope-from hselasky@svn.freebsd.org)
Received: (from hselasky@localhost)
	by svn.freebsd.org (8.14.3/8.14.3/Submit) id p0OHccPE000525;
	Mon, 24 Jan 2011 17:38:38 GMT
	(envelope-from hselasky@svn.freebsd.org)
Message-Id: <201101241738.p0OHccPE000525@svn.freebsd.org>
From: Hans Petter Selasky <hselasky@FreeBSD.org>
Date: Mon, 24 Jan 2011 17:38:38 +0000 (UTC)
To: src-committers@freebsd.org, svn-src-all@freebsd.org,
	svn-src-head@freebsd.org
X-SVN-Group: head
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Cc: 
Subject: svn commit: r217793 - head/sys/dev/usb
X-BeenThere: svn-src-head@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: SVN commit messages for the src tree for head/-current
	<svn-src-head.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/svn-src-head>
List-Post: <mailto:svn-src-head@freebsd.org>
List-Help: <mailto:svn-src-head-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/svn-src-head>,
	<mailto:svn-src-head-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 24 Jan 2011 17:38:38 -0000

Author: hselasky
Date: Mon Jan 24 17:38:37 2011
New Revision: 217793
URL: http://svn.freebsd.org/changeset/base/217793

Log:
  Add more sanity checks for USB_HOST_ALIGN input values. Re-factor existing
  checks for readability.
  
  Approved by:	thompsa (mentor)

Modified:
  head/sys/dev/usb/usb_freebsd.h

Modified: head/sys/dev/usb/usb_freebsd.h
==============================================================================
--- head/sys/dev/usb/usb_freebsd.h	Mon Jan 24 17:08:26 2011	(r217792)
+++ head/sys/dev/usb/usb_freebsd.h	Mon Jan 24 17:38:37 2011	(r217793)
@@ -46,12 +46,15 @@
 #define	USB_TD_GET_PROC(td) (td)->td_proc
 #define	USB_PROC_GET_GID(td) (td)->p_pgid
 
-#if defined(USB_HOST_ALIGN) && (USB_HOST_ALIGN != 0)
-/* USB_HOST_ALIGN is already defined and valid */
-#else
+#if (!defined(USB_HOST_ALIGN)) || (USB_HOST_ALIGN <= 0)
+/* Use default value. */
 #undef USB_HOST_ALIGN
 #define	USB_HOST_ALIGN    8		/* bytes, must be power of two */
 #endif
+/* Sanity check for USB_HOST_ALIGN: Verify power of two. */
+#if ((-USB_HOST_ALIGN) & USB_HOST_ALIGN) != USB_HOST_ALIGN
+#error "USB_HOST_ALIGN is not power of two."
+#endif
 #define	USB_FS_ISOC_UFRAME_MAX 4	/* exclusive unit */
 #define	USB_BUS_MAX 256			/* units */
 #define	USB_MAX_DEVICES 128		/* units */