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From: "Michael S. Zick" <lkml@morethan.org>
To: Alan Stern <stern@rowland.harvard.edu>
Cc: Oliver Neukum <oliver@neukum.org>, Jiri Kosina <jkosina@suse.cz>,
	linux-kernel@vger.kernel.org, linux-usb@vger.kernel.org
Subject: Re: Null Pointer BUG in uhci_hcd
Date: Tue, 7 Jul 2009 15:52:06 -0500	[thread overview]
Message-ID: <200907071552.09196.lkml@morethan.org> (raw)
In-Reply-To: <Pine.LNX.4.44L0.0907071559410.8221-100000@iolanthe.rowland.org>

On Tue July 7 2009, Alan Stern wrote:
> On Tue, 7 Jul 2009, Michael S. Zick wrote:
> 
> > Will add that to my list - -
> > I need to do that to find/fix that error path message flood loop in ehci anyway.
> 
> What EHCI message flood?
> 

Give me a chance to test what you have already put on my plate.
It isn't very interesting - when the driver shuts down a hub
for "problems found" (I can't be more specific at the moment)
It will try to immediately after resume the hub;
Which leads to it taking the hub out of service;
Which leads to it trying to resume the hub;
etc. etc. etc.
That message flood in the error recovery path.

Set: ignore_oc=1 on the command line and that will stop the flood
at the first message - but only because it hard-locks the kernel with irq's disabled.

On this machine, the "over current" sense is a false indication -
something is not within the expected range.

Thank goodness, no one has asked me to get this kernel certified
for life-support use (not possible, the VIA silicon isn't certified either).  ;)

Mike
> Alan Stern
> 
> 
> 



  reply	other threads:[~2009-07-07 20:52 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-07-05 22:20 Null Pointer BUG in uhci_hcd Michael S. Zick
2009-07-07  9:13 ` Jiri Kosina
2009-07-07 14:08   ` Oliver Neukum
2009-07-07 14:32     ` Michael S. Zick
2009-07-07 15:10     ` Alan Stern
2009-07-07 15:23       ` Michael S. Zick
2009-07-07 15:31         ` Alan Stern
2009-07-07 15:43           ` Michael S. Zick
2009-07-07 17:28             ` Alan Stern
2009-07-07 17:56               ` Michael S. Zick
2009-07-07 19:21                 ` Alan Stern
2009-07-07 19:51                   ` Michael S. Zick
2009-07-07 20:00                     ` Alan Stern
2009-07-07 20:52                       ` Michael S. Zick [this message]
2009-07-07 21:24                         ` Michael S. Zick
2009-07-08 19:54                           ` Alan Stern
2009-07-08 14:43                   ` Michael S. Zick
2009-07-08 16:30                     ` Michael S. Zick
2009-07-08 16:38                       ` Michael S. Zick
2009-07-11 19:07                         ` uhci_hcd fails to off-line device/hub on error condition Michael S. Zick
2009-07-12 15:16                           ` Alan Stern
2009-07-08 19:57                       ` Null Pointer BUG in uhci_hcd Alan Stern
2009-07-08 20:22                         ` Michael S. Zick
2009-07-08 21:02                           ` Alan Stern
2009-07-08 22:31                             ` Michael S. Zick
2009-07-09 14:18                               ` Alan Stern
2009-07-08 23:56                         ` Michael S. Zick
2009-07-08 23:59                           ` Michael S. Zick
2009-07-09 14:20                           ` Alan Stern
2009-07-09 14:46                             ` Michael S. Zick
2009-07-09 15:08                               ` Alan Stern
2009-07-09 16:07                                 ` Michael S. Zick
2009-07-09 20:58                                   ` Michael S. Zick

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