From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764735AbYETASm (ORCPT ); Mon, 19 May 2008 20:18:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758861AbYETASe (ORCPT ); Mon, 19 May 2008 20:18:34 -0400 Received: from xi.wantstofly.org ([83.160.184.112]:44567 "EHLO xi.wantstofly.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757419AbYETASd (ORCPT ); Mon, 19 May 2008 20:18:33 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=1148133259; d=wantstofly.org; h=date:from:to:cc:subject:message-id:mime-version:content-type: content-disposition:in-reply-to:user-agent; b=LiXo7UoEx/SkcEvzX1SGbVqe1XaL8P6SrbAiOfkCgZ5UVtfO9/+igJMmgiLm3 GM+pAXD0zgYAhRqOW/yULlwDg== Date: Tue, 20 May 2008 02:18:24 +0200 From: Lennert Buytenhek To: "Rafael J. Wysocki" , David Brownell , Alan Stern , Greg Kroah-Hartman Cc: Linux Kernel Mailing List , akpm@linux-foundation.org, nico@cam.org Subject: Re: [Bug #10713] ehci splatter in 2.6.26-rc2 Message-ID: <20080520001824.GA15878@xi.wantstofly.org> References: <7wuznNhcUqC.A.nUH.-rBMIB@albercik> <20080519231126.GA15099@xi.wantstofly.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080519231126.GA15099@xi.wantstofly.org> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 20, 2008 at 01:11:26AM +0200, Lennert Buytenhek wrote: > > This message has been generated automatically as a part of a report > > of recent regressions. > > > > The following bug entry is on the current list of known regressions > > from 2.6.25. Please verify if it still should be listed. > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=10713 > > Subject : ehci splatter in 2.6.26-rc2 > > Submitter : Lennert Buytenhek > > Date : 2008-05-14 11:24 (5 days old) > > References : http://marc.info/?l=linux-kernel&m=121076435420129&w=4 > > Handled-By : David Brownell > > Just re-checked, and this device (a USB to dual PS/2 cable) works > fine on 2.6.25 on this hardware: > > usb 1-1: new low speed USB device using orion-ehci and address 2 > usb 1-1: configuration #1 chosen from 1 choice > input: PS2 to USB AdapterA3 as /class/input/input0 > input: USB HID v1.10 Keyboard [PS2 to USB AdapterA3] on usb-orion-ehci.0-1 > input: PS2 to USB AdapterA3 as /class/input/input1 > input: USB HID v1.10 Mouse [PS2 to USB AdapterA3] on usb-orion-ehci.0-1 > > But on 2.6.26-rc3 it just gives me: > > usb 1-1: new low speed USB device using orion-ehci and address 2 > Unable to handle kernel NULL pointer dereference at virtual address 00000000 > pgd = c0004000 > [00000000] *pgd=00000000 > Internal error: Oops: 5 [#1] PREEMPT > Modules linked in: > CPU: 0 Not tainted (2.6.26-rc3 #347) > PC is at qh_append_tds+0x24c/0x47c > LR is at ehci_qtd_alloc+0x30/0x5c > pc : [] lr : [] psr: 00000093 > sp : c7cfdcb0 ip : c7e3c4c0 fp : c7cfdcfc > r10: ffc83080 r9 : 00000008 r8 : c7d12240 > r7 : 80000080 r6 : 00000080 r5 : 00000000 r4 : 00000002 > r3 : c7d3f000 r2 : 00000000 r1 : 40800000 r0 : 08085000 > Flags: nzcv IRQs off FIQs on Mode SVC_32 ISA ARM Segment kernel > Control: 0005317f Table: 00004000 DAC: 00000017 > Process khubd (pid: 79, stack limit = 0xc7cfc268) > Stack: (0xc7cfdcb0 to 0xc7cfe000) > [...] > Backtrace: > [] (qh_append_tds+0x0/0x47c) from [] (ehci_urb_enqueue+0x100/0xff4) > [] (ehci_urb_enqueue+0x0/0xff4) from [] (usb_hcd_submit_urb+0x824/0x91c) > [] (usb_hcd_submit_urb+0x0/0x91c) from [] (usb_submit_urb+0x224/0x260) > [] (usb_submit_urb+0x0/0x260) from [] (usb_start_wait_urb+0x44/0xac) > r6:c7d12240 r5:c7cfde80 r4:00000000 > [] (usb_start_wait_urb+0x0/0xac) from [] (usb_control_msg+0xc8/0xec) > r8:00000000 r7:00000100 r6:fffffff4 r5:00000040 r4:c7e3dc20 > [] (usb_control_msg+0x0/0xec) from [] (hub_port_init+0x274/0x5e4) > [] (hub_port_init+0x0/0x5e4) from [] (hub_thread+0x608/0xc10) > [] (hub_thread+0x0/0xc10) from [] (kthread+0x5c/0x94) > [] (kthread+0x0/0x94) from [] (do_exit+0x0/0x67c) > r6:00000000 r5:00000000 r4:00000000 > Code: e51bc040 e5932000 e51c309c e1520003 (15923000) > ---[ end trace ce1992535f2e8e4d ]--- > note: khubd[79] exited with preempt_count 1 > > If you have no idea what might have caused this to creep in, I guess > I'll have to bisect it? A bisect turns up this: 7329e211b987a493cbcfca0e98c60eb108ab42df is first bad commit commit 7329e211b987a493cbcfca0e98c60eb108ab42df Author: Alan Stern Date: Thu Apr 3 18:02:56 2008 -0400 USB: root hubs don't lie about their number of TTs Currently EHCI root hubs enumerate with a bDeviceProtocol code indicating that they possess a Transaction Translator. However the vast majority of controllers do not; they rely on a companion controller to handle full- and low-speed communications. This patch (as1064) changes the root-hub device descriptor to match the actual situation. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman And indeed, reverting this commit from 2.6.26-rc3 makes my system stop oopsing when I plug in the USB-PS/2 adapter (a low speed device), and makes it work again as it did in 2.6.25. Any other info I can provide or tests I can run? thanks, Lennert