Bug 14147

Summary:	System unresponsive if I unplug network cable while ethtool -p is running
Product:	Drivers	Reporter:	dave graham (david.graham)
Component:	Network	Assignee:	Bruce Allan (bruce.w.allan)
Status:	CLOSED CODE_FIX
Severity:	normal	CC:	alan, eric.dumazet, jesse.brandeburg, tushar.n.dave
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.30	Subsystem:
Regression:	No	Bisected commit-id:

Description dave graham 2009-09-09 00:05:57 UTC

When a user runs the "ethtool -p ethX" to identify the physical interface by flashing the appropriate interface LED, and then removes the cable at that interface, the keyboard locks up. This is naturally annoying to customers with multi-port systems, who wish to use ethtool -p so that they can disconnect/connect interface cables to appropriate ports. 

I am told that this is because "the RTNL lock is held by ethtool, and the link [down] message needs the RTNL", which would, I think, make this a kernel issue. 

This has been known about within INTEL for over 3 years, but only recently come to my attention. I have verified it on a 2.6.30 system using a default kernel configuration and the e1000e driver.

Comment 1 Andrew Morton 2009-09-11 19:55:49 UTC

(switched to email.  Please respond via emailed reply-to-all, not via the
bugzilla web interface).

On Wed, 9 Sep 2009 00:06:10 GMT
bugzilla-daemon@bugzilla.kernel.org wrote:

> http://bugzilla.kernel.org/show_bug.cgi?id=14147
> 
>            Summary: System unresponsive if I unplug network cable while
>                     ethtool -p is running
>            Product: Networking
>            Version: 2.5
>     Kernel Version: 2.6.30
>           Platform: All
>         OS/Version: Linux
>               Tree: Mainline
>             Status: NEW
>           Severity: normal
>           Priority: P1
>          Component: Other
>         AssignedTo: acme@ghostprotocols.net
>         ReportedBy: david.graham@intel.com
>         Regression: No
> 
> 
> When a user runs the "ethtool -p ethX" to identify the physical interface by
> flashing the appropriate interface LED, and then removes the cable at that
> interface, the keyboard locks up. This is naturally annoying to customers
> with
> multi-port systems, who wish to use ethtool -p so that they can
> disconnect/connect interface cables to appropriate ports. 
> 
> I am told that this is because "the RTNL lock is held by ethtool, and the
> link
> [down] message needs the RTNL", which would, I think, make this a kernel
> issue. 
> 
> This has been known about within INTEL for over 3 years, but only recently
> come
> to my attention. I have verified it on a 2.6.30 system using a default kernel
> configuration and the e1000e driver.
> 

hah.  cute.

Comment 2 Tushar 2011-02-23 00:45:50 UTC

I reproduced this issue on F14 and e1000e driver.

Comment 3 Jesse Brandeburg 2012-06-13 17:12:20 UTC

Why was this assigned to e1000e owner (bruce)?  It is a kernel bug that is basically a design issue, should probably be assigned to network core owner.  Not sure if it will ever be fixed, but would be nice.

Comment 4 Bruce Allan 2012-06-13 17:54:44 UTC

This has been fixed for almost a year now.

Comment 5 Alan 2012-06-13 19:28:22 UTC

Thanks