Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757127AbZLDTer (ORCPT ); Fri, 4 Dec 2009 14:34:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755936AbZLDTeq (ORCPT ); Fri, 4 Dec 2009 14:34:46 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:42663 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1755093AbZLDTep (ORCPT ); Fri, 4 Dec 2009 14:34:45 -0500 Date: Fri, 4 Dec 2009 14:34:46 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Ondrej Zary cc: linux-usb@vger.kernel.org, Subject: Re: debugging oops after disconnecting Nexio USB touchscreen In-Reply-To: <200912042017.36459.linux@rainbow-software.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1358 Lines: 32 On Fri, 4 Dec 2009, Ondrej Zary wrote: > Just found why it was sometimes hard to reproduce a problem. Sometimes the > devices are controlled by uhci_hcd and sometimes by ehci_hcd. It seems to > be random and can change on every reboot. It shouldn't change. The hub you plug into (the D-Link hub) should always be controlled by ehci-hcd. Can you post a dmesg log showing what happens on bootup for a case where the hub ends up under uhci-hcd? > With uhci_hcd, rmmod works fine. With ehci_hcd, rmmod hangs the bus - all > urbs fail with -ENOENT: > f67265e8 1428021080 S Bi:1:009:2 -115 128 < > f67265e8 1431508327 C Bi:1:009:2 -108 0 > f6726718 1458252464 S Co:1:007:0 s 40 09 0001 0000 0000 0 > f6726718 1463261404 C Co:1:007:0 -2 0 > f6726978 1463261428 S Co:1:002:0 s 23 08 0070 0001 0000 0 > f6726718 1463261509 S Co:1:007:0 s 40 00 0000 0000 0000 0 > f6726978 1464273397 C Co:1:002:0 -2 0 > f6726718 1468273397 C Co:1:007:0 -2 0 This may be a bug in ehci-hcd, a bug in your EHCI hardware, or a bug in the hub. Can you try using a different high-speed hub to see if it makes any difference? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/