Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755935AbXKWQVT (ORCPT ); Fri, 23 Nov 2007 11:21:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752296AbXKWQVL (ORCPT ); Fri, 23 Nov 2007 11:21:11 -0500 Received: from netrider.rowland.org ([192.131.102.5]:2391 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752111AbXKWQVK (ORCPT ); Fri, 23 Nov 2007 11:21:10 -0500 Date: Fri, 23 Nov 2007 11:21:08 -0500 (EST) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: "Kirill A. Shutemov" cc: Marin Mitov , Kernel development list Subject: Re: [linux-usb-devel] 2.6.24-rc3-mm1: usb mouse doesn't work In-Reply-To: <20071123051955.GA28946@localhost.localdomain> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1965 Lines: 48 On Fri, 23 Nov 2007, Kirill A. Shutemov wrote: > On [Thu, 22.11.2007 21:51], Alan Stern wrote: > > On Thu, 22 Nov 2007, Marin Mitov wrote: > > > > > > > > I've had some strangenesses with USB lately. Sometimes running `lsusb' > > > > > > makes the USB system notice a newly attached device. > > > > > > > > > > No. But I have new messages in dmesg: > > > > > > > > > > uhci_hcd 0000:00:1d.3: FGR not stopped yet! > > > > > uhci_hcd 0000:00:1d.2: FGR not stopped yet! > > > > > uhci_hcd 0000:00:1d.1: FGR not stopped yet! > > > > > uhci_hcd 0000:00:1d.0: FGR not stopped yet! > > > > > > > > > > > Is that "FGR not stopped yet!" messgae new behaviour? > > > > > > > > > > It is a new message since 2.6.24-rc3. I have never try -mm tree before. > > > > > > > > These messages could indicate a timing problem. You can see the code > > > > that writes the messages near the end of wakeup_rh() in > > > > drivers/usb/host/uhci-hcd.c. > > > > > > > > The message gets written if the controller hardware hasn't turned off a > > > > particular bit after a 4-us delay. If the udelay() function wasn't > > > > working right, it could cause this problem. > > > > > > udelay() _is_ OK for 2.6.24-rc3, so it is not the cause of the problem > > > > But is it OK for 2.6.24-rc3-mm1? Kirill said specifically that > > 2.6.24-rc3 does not display the message but 2.6.24-rc3-mm1 does. > > How can I test it? Add some printk statements to the wakeup_rh() routine: Display the value of inw(uhci->io_addr + USBCMD) in hex, both before and after the udelay(4) line. Try doing this for both 2.6.24-rc3 and 2.6.24-rc3-mm1 so you can compare the values for the two different kernels. Also, enable CONFIG_PRINTK_TIME. 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/