Re: 2.6.37-rc2 regression: usb network hotplug

[Eric Dumazet <eric.dumazet@gmail.com>]

Le mercredi 17 novembre 2010 à 13:10 +0100, Patrick Schaaf a écrit :
> When trying out 2.6.37-rc2 on my Dell Latitude D630 laptop, I notice a
> regression, compared to plain 2.6.36, related to USB unplugging my N900
> (cdc_ether network device).
> 
> The usb0 interface is configured to automatically plug into a bridge
> group, if that matters.
> 
> On 2.6.36 I can unplug and replug the device properly.
> 
> Under 2.6.37-rc2, the first plugging works, the device is reachable as
> desired, but after unplugging it the first time, I receive the following
> message every 10 seconds:
> 
>  kernel:[  149.632104] unregister_netdevice: waiting for usb0 to become
> free. Usage count = 1
> 
> The usb0 device is gone at that point. Replugging does not work.
> 
> When I reboot into the same kernel, a list of "cannot reset port"
> messages is apparent in the boot logs, as appended. This disappears
> after shutting down the machine.
> 
> I'll gladly try out patches that could fix this, or try out other things
> to help diagnose.
> 
> best regards
>   Patrick
> 
> <3>[    4.449056] usb 6-1.2: device not accepting address 3, error -71
> <3>[    4.452793] hub 6-1:1.0: cannot disable port 2 (err = -71)
> <3>[    4.454787] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.456787] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.458787] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.460787] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.462786] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.464491] hub 6-1:1.0: Cannot enable port 2.  Maybe the USB
> cable is bad?
> <3>[    4.466787] hub 6-1:1.0: cannot disable port 2 (err = -71)
> <3>[    4.468785] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.470786] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.472787] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.474780] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.476784] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.478261] hub 6-1:1.0: Cannot enable port 2.  Maybe the USB
> cable is bad?
> <3>[    4.479773] hub 6-1:1.0: cannot disable port 2 (err = -71)
> <3>[    4.481773] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.483772] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.485778] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.487787] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.489789] hub 6-1:1.0: cannot reset port 2 (err = -71)
> <3>[    4.491052] hub 6-1:1.0: Cannot enable port 2.  Maybe the USB
> cable is bad?
> <3>[    4.492788] hub 6-1:1.0: cannot disable port 2 (err = -71)
> <3>[    4.494079] hub 6-1:1.0: unable to enumerate USB device on port 2
> <3>[    4.495787] hub 6-1:1.0: cannot disable port 2 (err = -71)
> <3>[    4.497790] hub 6-1:1.0: hub_port_status failed (err = -71)
> <6>[    4.499100] usb 6-1: USB disconnect, address 2
> 

Please try

http://patchwork.ozlabs.org/patch/71354/