Subject: Re: [PATCH net] net: dsa: fix bonding with ARP monitoring by updating trans_start manually

From: Jakub Kicinski <[email-masked]>
Date: Fri, 15 Jul 2022 17:19:59 -0700

On Sat, 16 Jul 2022 00:14:44 +0000 Vladimir Oltean wrote:
> On Fri, Jul 15, 2022 at 05:00:42PM -0700, Jakub Kicinski wrote:
> > On Sat, 16 Jul 2022 02:26:41 +0300 Vladimir Oltean wrote:  
> > > Documentation/networking/bonding.rst points out that for ARP monitoring
> > > to work, dev_trans_start() must be able to verify the latest trans_start
> > > update of any slave_dev TX queue. However, with NETIF_F_LLTX,
> > > netdev_start_xmit() -> txq_trans_update() fails to do anything, because
> > > the TX queue hasn't been locked.
> > > 
> > > Fix this by manually updating the current TX queue's trans_start for
> > > each packet sent.
> > > 
> > > Fixes: 2b86cb829976 ("net: dsa: declare lockless TX feature for slave ports")
> > > Reported-by: Brian Hutchinson <[email-masked]>
> > > Signed-off-by: Vladimir Oltean <[email-masked]>  
> > 
> > Did you see my discussion with Jay? Let's stop the spread of this
> > workaround, I'm tossing..  
> 
> No, I didn't, could you summarize the alternative proposal?

Make bonding not depend on a field which is only valid for HW devices
which use the Tx watchdog. Let me find the thread...
https://lore.kernel.org/all/[email-masked]/