From owner-freebsd-stable@FreeBSD.ORG Wed Aug 15 17:05:31 2012 Return-Path: <owner-freebsd-stable@FreeBSD.ORG> Delivered-To: stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 352F81065672 for <stable@freebsd.org>; Wed, 15 Aug 2012 17:05:31 +0000 (UTC) (envelope-from paul@gromit.dlib.vt.edu) Received: from lennier.cc.vt.edu (lennier.cc.vt.edu [198.82.162.213]) by mx1.freebsd.org (Postfix) with ESMTP id E208E8FC08 for <stable@freebsd.org>; Wed, 15 Aug 2012 17:05:30 +0000 (UTC) Received: from zidane.cc.vt.edu (zidane.cc.vt.edu [198.82.163.227]) by lennier.cc.vt.edu (8.13.8/8.13.8) with ESMTP id q7FGRoOA030794 for <stable@freebsd.org>; Wed, 15 Aug 2012 12:27:50 -0400 Received: from auth3.smtp.vt.edu (EHLO auth3.smtp.vt.edu) ([198.82.161.152]) by zidane.cc.vt.edu (MOS 4.3.3-GA FastPath queued) with ESMTP id UEO92355; Wed, 15 Aug 2012 12:27:50 -0400 (EDT) Received: from pmather.tower.lib.vt.edu (pmather.tower.lib.vt.edu [128.173.51.28]) (authenticated bits=0) by auth3.smtp.vt.edu (8.13.8/8.13.8) with ESMTP id q7FGRoM9001256 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO) for <stable@freebsd.org>; Wed, 15 Aug 2012 12:27:50 -0400 From: Paul Mather <paul@gromit.dlib.vt.edu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Date: Wed, 15 Aug 2012 12:27:49 -0400 Message-Id: <6DFEFF91-F9A9-4C64-8D1C-FB7A73BC7A2E@gromit.dlib.vt.edu> To: stable@freebsd.org Mime-Version: 1.0 (Apple Message framework v1084) X-Mailer: Apple Mail (2.1084) X-Mirapoint-Received-SPF: 198.82.161.152 auth3.smtp.vt.edu paul@gromit.dlib.vt.edu 5 none X-Junkmail-Status: score=10/50, host=zidane.cc.vt.edu X-Junkmail-Signature-Raw: score=unknown, refid=str=0001.0A020207.502BCE06.0068,ss=1,re=0.000,fgs=0, ip=0.0.0.0, so=2011-07-25 19:15:43, dmn=2011-05-27 18:58:46, mode=single engine X-Junkmail-IWF: false Cc: Subject: uhci0 excessive interrupts---how can I disable or reset specific USB port? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org> List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, <mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe> List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable> List-Post: <mailto:freebsd-stable@freebsd.org> List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help> List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, <mailto:freebsd-stable-request@freebsd.org?subject=subscribe> X-List-Received-Date: Wed, 15 Aug 2012 17:05:31 -0000 I am running FreeBSD/amd64 9-STABLE (built Mon Jul 23 10:45:51 EDT 2012) = on a Dell Optiplex 760 and, today, noticed I had almost 30% system CPU = load in top even when the system was idle. A perusal of vmstat revealed = the cause to be excessive interrupts on uhci0, even though nothing was = plugged into that USB port: # vmstat -i interrupt total rate irq4: uart0 22 0 irq16: uhci0 617002282738 310969 irq23: uhci3 ehci1 83 0 irq256: hpet0:t0 135818421 68 irq257: hpet0:t1 2222659301 1120 irq264: em0 29529304 14 irq265: ahci0 11132506 5 Total 619401422375 312178 Because I am only using the front USB ports on that hardware, I thought = I would disable the other (rear) USB ports in the BIOS. I rebooted and = duly disabled them. However, when FreeBSD booted, it appeared to ignore = the BIOS setting: all the USB ports were probed as usual. (The high = interrupts had vanished, though that might have been due to FreeBSD = correctly shutting down the controllers at shutdown, or just the act of = rebooting itself.) I added "hint.uhci.0.disabled=3D1" to /boot/loader.conf (hoping it would = disable uhci0), but, again all the USB ports appeared in the boot = probes. (However, it *appears* as if uhci0 has been disabled because = the "irq16: uhci0" line no longer appears in "vmstat -i". However, all = the same ugen devices appear in /dev.) Is there a way of disabling a specific USB controller that you don't = want to use? If so, how? I looked at usbconfig, but that appears to me = to be more about controlling devices plugged in to a USB port rather = than the port itself. The "reset" command of usbconfig appears to be = about resetting USB devices, not ports. If I can't disable a specific USB port, is there a way to reset it = without rebooting? If I ever get another crazy interrupt storm like I = noticed today it would be nice to be able to stop it without having to = do a reboot. Cheers, Paul.