From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from iolanthe.rowland.org ([192.131.102.54]:55670 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752040Ab1HHOi2 (ORCPT ); Mon, 8 Aug 2011 10:38:28 -0400 Date: Mon, 8 Aug 2011 10:38:27 -0400 (EDT) From: Alan Stern To: Adam Baker cc: Theodore Kilgore , Jean-Francois Moine , Linux Media Mailing List , , Hans de Goede Subject: Re: [Workshop-2011] Media Subsystem Workshop 2011 In-Reply-To: <201108080130.57394.linux@baker-net.org.uk> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-media-owner@vger.kernel.org List-ID: On Mon, 8 Aug 2011, Adam Baker wrote: > Further testing reveals the situation is more complex than I first thought - > the behaviour I get depends upon whether what gets plugged in is a full speed > or a high speed device. After I've run the test of running gphoto whilst > streaming from a supported dual mode camera, lsusb fails to recognise a high > speed device plugged into the port the camera was plugged into (it works fine > if plugged in elsewhere) and lsusb hangs if I plug in a new low speed or full > speed device. When I get some time I'll see if I can recreate the problem > using libusb with a totally different device. Looking around my pile of USB > bits for something full speed with a kernel driver I've got a PL2303 serial > port. Would that be a good choice to test with? I have no idea. But the symptoms you describe are indicative of a hardware problem, not a driver bug. > Just for reference with a full speed device I see the messages below in dmesg > with the second one only appearing when I do lsusb > [10832.128039] usb 3-2: new full speed USB device using uhci_hcd and address > 34 > [10847.240031] usb 3-2: device descriptor read/64, error -110 > > and with a high speed device I see a continuous stream of > [11079.820097] usb 1-4: new high speed USB device using ehci_hcd and address > 103 > [11079.888355] hub 1-0:1.0: unable to enumerate USB device on port 4 > [11080.072377] hub 1-0:1.0: unable to enumerate USB device on port 4 > [11080.312053] usb 1-4: new high speed USB device using ehci_hcd and address > 105 > [11080.380418] hub 1-0:1.0: unable to enumerate USB device on port 4 > [11080.620030] usb 1-4: new high speed USB device using ehci_hcd and address > 106 > [11080.688322] hub 1-0:1.0: unable to enumerate USB device on port 4 The dmesg log is relatively uninformative unless you enable CONFIG_USB_DEBUG in the kernel build. Have you tried running these tests on a different computer, preferably one using a different chipset? Alan Stern