Re: [BUG] bisected: PandaBoard smsc95xx ethernet driver error from USB timeout

[Frank Rowand <frank.rowand@am.sony.com>]

On 03/21/13 07:41, Alan Stern wrote:
> On Wed, 20 Mar 2013, Frank Rowand wrote:
> 
>> Hi All,
>>
>> Not quite sure quite where the problem is (USB, OMAP, smsc95xx driver, other???),
>> so casting the nets wide...
>>
>> The PandaBoard frequently fails to boot with an eth0 error when mounting
>> the root file system via NFS (ethernet driver fails due to a USB timeout;
>> no ethernet means NFS won't work).  A typical set of error messages is:
>>
>> [    3.264373] smsc95xx 1-1.1:1.0: usb_probe_interface
>> [    3.269500] smsc95xx 1-1.1:1.0: usb_probe_interface - got id
>> [    3.275543] smsc95xx v1.0.4
>> [    8.078674] smsc95xx 1-1.1:1.0: eth0: register 'smsc95xx' at usb-ehci-omap.0-1.1, smsc95xx USB 2.0 Ethernet, 82:b9:1d:fa:67:0d
>> [    8.091003] hub 1-1:1.0: state 7 ports 5 chg 0000 evt 0002
>> [   13.509918] usb 1-1.1: swapper/0 timed out on ep0out len=0/4
>> [   13.515869] smsc95xx 1-1.1:1.0: eth0: Failed to write register index 0x00000108
>> [   13.523559] smsc95xx 1-1.1:1.0: eth0: Failed to write ADDRL: -110
>> [   13.529998] IP-Config: Failed to open eth0
>>
>> I have bisected this to:
>>
>>   commit 18aafe64d75d0e27dae206cacf4171e4e485d285
>>   Author: Alan Stern <stern@rowland.harvard.edu>
>>   Date:   Wed Jul 11 11:23:04 2012 -0400
>>
>>      USB: EHCI: use hrtimer for the I/O watchdog
> 
> I don't understand how that commit could cause a timeout unless there 
> are at least two other bugs present in your system.

Yes, I would not be at all surprised if this commit merely exposes a
problem in other code.  That is why I included so many different people
and subsystems on the email distribution list.

< snip >

-Frank