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

[Alan Stern]

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@xxxxxxxxxxxxxxxxxxx>
>   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.

> Note that to compile this version of the kernel, an additional fix must
> also be applied:
> 
>   commit ba5952e0711b14d8d4fe172671f8aa6091ace3ee
>   Author: Ming Lei <ming.lei@xxxxxxxxxxxxx>
>   Date:   Fri Jul 13 17:25:24 2012 +0800
> 
>      USB: ehci-omap: fix compile failure(v1)
> 
> The symptom can be worked around by retrying the USB access if a timeout
> occurs.  This is clearly _not_ the fix, just a hack that I used to
> investigate the problem:
> 
>   http://article.gmane.org/gmane.linux.rt.user/9773
> 
> My kernel configuration is:
> 
>   arch/arm/configs/omap2plus_defconfig
> 
>   plus to get the ethernet driver I add:
> 
>     CONFIG_USB_EHCI_HCD
>     CONFIG_USB_NET_SMSC95XX
> 
> I found the problem on 3.6.11, but have not replicated it on 3.9-rcX
> yet because my config fails to build on 3.9-rc1 and 3.9-rc2.  I'll try
> to work on that issue tomorrow.

Let me know how it works out.

Alan Stern

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