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From: John Baldwin <jhb@freebsd.org>
To: freebsd-net@freebsd.org
Subject: Re: IFF_DRV_OACTIVE handling in *_stop() for intel nic drivers ?
Date: Mon, 23 Dec 2013 12:23:56 -0500
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Cc: Jack F Vogel <jfv@freebsd.org>, Adrian Chadd <adrian@freebsd.org>,
 Luigi Rizzo <rizzo@iet.unipi.it>, Mike Karels <mike@karels.net>,
 "net@freebsd.org" <net@freebsd.org>
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On Friday, December 13, 2013 8:23:08 pm Luigi Rizzo wrote:
> On Fri, Dec 13, 2013 at 06:08:55PM -0600, Mike Karels wrote:
> > > ... OACTIVE by design is racy. We should just not be using it in newer 
drivers.
> > 
> > > I think the correct thing to do is to just plain ignore setting it ever.
> > 
> > I agree; OACTIVE is totally obsolete for drivers that use if_transmit,
> > and not particularly useful for other drivers.  It might be time to remove
> > OACTIVE, or define it to be 0.  (And I added the original IFF_OACTIVE).
> 
> ok thanks for the clarification

In particular, it is useless (and AFAIK ignored) if you are using if_transmit.
I've fixed it in igb before, has it crept back in?  It should only be used
in drivers using if_start() when the ifq is full, and cleared when a tx
completion interrupt fires.

-- 
John Baldwin