Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757374AbZLDVYX (ORCPT ); Fri, 4 Dec 2009 16:24:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757277AbZLDVYV (ORCPT ); Fri, 4 Dec 2009 16:24:21 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:43782 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1757289AbZLDVYT (ORCPT ); Fri, 4 Dec 2009 16:24:19 -0500 Date: Fri, 4 Dec 2009 16:24:25 -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: <200912042055.32747.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: 3017 Lines: 70 On Fri, 4 Dec 2009, Ondrej Zary wrote: > [ 3.712039] usb 2-1: new full speed USB device using uhci_hcd and address 2 > [ 3.726791] kjournald starting. Commit interval 5 seconds > [ 3.726817] EXT3-fs (sda2): mounted filesystem with ordered data mode > [ 3.851384] usb 2-1: not running at top speed; connect to a high speed hub > [ 3.859379] usb 2-1: New USB device found, idVendor=2001, idProduct=f103 > [ 3.859387] usb 2-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 > [ 3.862635] hub 2-1:1.0: USB hub found > [ 3.864385] hub 2-1:1.0: 7 ports detected That's the problem. Notice the "not running at top speed" message? Something went wrong when the hub was detected. It could be a problem in your EHCI controller or a problem in the hub. You can get more information about this by unplugging the hub, running usbmon (on the 0u file), and then plugging the hub back in. > diff between ehci and uhci logs: > There seems to be some problem with timing. > Also order of ehci_usb vs uhci_usb loading changes. That order doesn't matter much. But this... > --- dmesg-ehci.txt- 2009-12-04 20:01:39.000000000 +0100 > +++ dmesg-uhci.txt- 2009-12-04 20:01:31.000000000 +0100 > @@ -144,10 +144,9 @@ > Console: colour VGA+ 80x25 > console [tty0] enabled > hpet clockevent registered > - Fast TSC calibration failed > - TSC: PIT calibration matches HPET. 1 loops > - Detected 1608.000 MHz processor. > - Calibrating delay loop (skipped), value calculated using timer frequency.. 3216.00 BogoMIPS (lpj=6432000) > + Fast TSC calibration using PIT > + Detected 1608.123 MHz processor. > + Calibrating delay loop (skipped), value calculated using timer frequency.. 3216.24 BogoMIPS (lpj=6432492) > Security Framework initialized > SELinux: Disabled at boot. > Mount-cache hash table entries: 512 > @@ -180,7 +179,7 @@ > CPU1: Thermal monitoring enabled (TM2) > CPU1: Intel(R) Atom(TM) CPU N270 @ 1.60GHz stepping 02 > Brought up 2 CPUs > - Total of 2 processors activated (9326.27 BogoMIPS). > + Total of 2 processors activated (6432.20 BogoMIPS). Those two differences seem strange to me. You might want to report it in a new email thread on LKML. You might also want to see if the same thing happens with a 2.6.32 kernel. > > 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? > > Yes, I'll try it next week (I have only remote access now). > I have different 7-port hub available to test (should be with Philips chipset). It's worth a try. Still, the original problem you saw (the oops in ehci-hcd) is in software, not in hardware, so the hub can't be entirely responsible. 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/