Re: [net-next 04/14] net: Fix issue with netdev_tx_reset_queue not resetting queue from XOFF state

From: John Fastabend <redacted>
Date: Sat, 21 Apr 2012 09:27:31 -0700

On 4/20/2012 11:01 PM, Tom Herbert wrote:

quoted

quoted

I don't recall the exact reason now, as John said I think it had to do
with the ethtool tests not using the same cleanup routine and leaving
us in a bad state.  I am pretty sure there was some path in which
where the call was didn't work but I do not recall the exact details
now.  Most of the reason for moving it is due to the fact that the
reset is now also clearing the bit, and from the driver perspective we
didn't need it in two places.  After looking it all over again, I
suppose this causes a cosmetic issue for the bql "inflight" statistic
in sysfs since the value will be retained until the interface is
brought back up with this change.  Is that an issue or something that
can be lived with since the interface isn't active anyway in this
case?

On the surface, it seems cleaner and probably a simpler convention to
clear the state when the buffers are being freed.  If there's a good
reason not to do this for igb, it makes me wonder if this should be
done the same way in other drivers...

Tom

Just dug up the old thread. This was to fix a bug that byte queue limits
was causing with some of the loopback tests evoked from ethtool. The
loopback test uses a separate path to free the buffers which wasn't
calling netdev_tx_reset_queue().

We should likely just explicitly clear the state in each routine rather
than try to be clever IMO.

Agreed.