mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: David Brownell <david-b@pacbell.net>
To: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: linux-kernel@vger.kernel.org, Nicolas Pitre <nico@cam.org>,
	Sylver Bruneau <sylver.bruneau@googlemail.com>,
	Byron Bradley <byron.bbradley@gmail.com>,
	Martin Michlmayr <tbm@cyrius.com>
Subject: Re: ehci splatter in 2.6.26-rc2
Date: Wed, 14 May 2008 06:11:45 -0700	[thread overview]
Message-ID: <200805140611.45897.david-b@pacbell.net> (raw)
In-Reply-To: <20080514112429.GA25926@xi.wantstofly.org>

On Wednesday 14 May 2008, Lennert Buytenhek wrote:
> On 2.6.26-rc2, plugging in a certain USB device (haven't tested yet
> with other devices) gives me (on two different ARM boards) the oops
> below.
> 
> Anyone else seeing the same?

I have no ARM running EHCI, but I can report it's OK
for me on x86 (limited testing) ... I'd expect to have
heard *very* load screams by now if this was common.


> 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: 17 [#1] PREEMPT
> Modules linked in:
> CPU: 0    Not tainted  (2.6.26-rc2 #340)
> PC is at qh_append_tds+0x24c/0x44c
> LR is at ehci_qtd_alloc+0x30/0x5c
> ...
> [<c0223668>] (qh_append_tds+0x0/0x44c) from [<c0225470>]
>		(ehci_urb_enqueue+0x100 /0xfb8) 
> [<c0225370>] (ehci_urb_enqueue+0x0/0xfb8) from [<c02163e8>]
>		(usb_hcd_submit_urb+ 0x824/0x91c) 

Nothing in that vicinity should have changed in ages,
which makes me wonder if it's really EHCI which is
triggering this.

The only thing coming vaguely to mind is that this may
have to do with dma-coherent memory allocations.  If
the platform support for that has any goofage, you might
be able to elicit different behaviors with dmapool debug
(enable CONFIG_DEBUG_SLAB or CONFIG_SLUB_DEBUG_ON).

- Dave




      reply	other threads:[~2008-05-14 13:12 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-05-14 11:24 Lennert Buytenhek
2008-05-14 13:11 ` David Brownell [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=200805140611.45897.david-b@pacbell.net \
    --to=david-b@pacbell.net \
    --cc=buytenh@wantstofly.org \
    --cc=byron.bbradley@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=nico@cam.org \
    --cc=sylver.bruneau@googlemail.com \
    --cc=tbm@cyrius.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

all inboxes | Powered by JetHome®