Subject: Re: [PATCH] tg3: ethtool phys_id default (rev2)

From: Stephen Hemminger <[email-masked]>
Date: Mon, 25 Feb 2008 07:58:14 -0800

On Sun, 24 Feb 2008 07:42:06 +0200
"Eliezer Tamir" <[email-masked]> wrote:

> 
> On Sat, 2008-02-23 at 19:52 -0800, David Miller wrote:
> > From: "Michael Chan" <[email-masked]>
> > Date: Fri, 22 Feb 2008 11:16:42 -0800
> > 
> > > On Fri, 2008-02-22 at 10:24 -0800, Stephen Hemminger wrote:
> > > > When asked to blink LEDs the tg3 driver behaves when using:
> > > > 	ethtool -p ethX
> > > > The default value for data is zero, and other drivers interpret this
> > > > as blink forever (or at least a really long time).  The tg3 driver
> > > > interprets this as blink once.  All drivers should have the same
> > > > behaviour.
> ...
> > > We should do this across the board for bnx2, bnx2x, and niu as well.
> > 
> > Agreed.
> 
> Doesn't this mean that ethtool -p will hold the RTNL lock forever?
> Is this a good idea?
> 
> For example on the Red Hat machine I have here if you do:
> 
> ethtool -p eth2 100000 &
> reboot
> 
> Various things the shutdown scripts try to do will fail because of the
> held RTNL lock. in the end the script dies and the machine does not
> reboot.

1. ethtool -p is only used by root to identify interfaces, so in practice
   this is not a real problem.

2. ethtool -p is interruptible, and the reboot process sends a SIGTERM to
   all processes.