Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751840AbYKFTfG (ORCPT ); Thu, 6 Nov 2008 14:35:06 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750910AbYKFTey (ORCPT ); Thu, 6 Nov 2008 14:34:54 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:41876 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1750804AbYKFTey (ORCPT ); Thu, 6 Nov 2008 14:34:54 -0500 Date: Thu, 6 Nov 2008 14:34:53 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: Norbert Preining , Pete Zaitcev cc: Mattia Dongili , Kernel development list , USB list Subject: Re: usb device not showing up In-Reply-To: <20081106171958.GA17270@gamma.logic.tuwien.ac.at> 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: 2160 Lines: 58 On Thu, 6 Nov 2008, Norbert Preining wrote: > Here it is. Sequence of events: > - turn off the laptop, physically > - turn it on > - boot in to linux with modular usb and init=/bin/bash > - mount /proc, /sys, /sys/kernel/debug > - modprobe usbmon (file /sys/kernel/debug/usbmon/{0s,0u} are present) > - start some getty to have more terminals, mount / rw > > - cat /sys/kernel/debug/usbmon/0u > usbmon-bad.txt > - modprobe uhci-hcd > - modprobe hso > > The device does not show up in /proc/bus/usb/devices (mounted before > probing and debugging), only bus 4 hub is there. Okay. In the earlier (working) test, the modem showed up on bus 4, not bus 2. Not that it matters much -- the modem didn't show up at all in this test, on any bus. Its USB interface seems to be electrically disconnected or turned off. Evidently the system needs to do something to tell the modem that it should start working, but I have no idea what that would be. It's not a USB issue; as far as USB is concerned the device just isn't there at all. Maybe the hso developers will have some idea. Or maybe it's controlled by a setting in your laptop's BIOS. > /sys/bus/usb/drivers/hso/ shows > bind module new_id uevent unbind > > - sync > - cat process > > Outcome is the attached usbmon-bad.txt > > This is the one where the device does not show up. Interestingly, this trace appears to be missing some events. There's a gap between timestamps 4284549076 and 4284645743 (the timestamps are in the second column) where we should see the initialization of bus 5 and bus 6. Instead there's a 100-ms delay in which nothing happens, followed later on by the second initialization phase for those two buses. I have to wonder... Did you remove any part of the trace? Did usbmon malfunction? Did parts of the initialization for those two buses really get skipped (I can't imagine how)? Pete, any ideas? 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/