Re: [PATCH net] net: spacemit: Hold RTNL lock in emac_resume() and emac_suspend()

[Ali Tariq]

On 11/6/26 2:43 PM, Troy Mitchell wrote:
> On Thu,  5 Nov 2026 17:34:37 +0500, Ali Tariq wrote:
> > @@ -2056,7 +2059,9 @@ static int emac_suspend(struct device *dev)
> >   		return 0;
> >   	}
> >   
> > +	rtnl_lock();
> >   	emac_stop(ndev);
> > +	rtnl_unlock();
> >   
> >   	clk_disable_unprepare(priv->bus_clk);
> >   	netif_device_detach(ndev);
> This can deadlock. emac_stop() -> emac_down() calls
> cancel_work_sync(&priv->tx_timeout_task) with RTNL now held, while
> emac_tx_timeout_task() starts with rtnl_lock().

Thanks Troy, that makes sense.

For the deadlock, I think the correct function to call is rtnl_trylock() 
inside the emac_tx_timeout_task(), which would return if the lock is 
already held and will hold the lock if it is not.

What are your thoughts on this? Does a v2 changing rtnl_lock() to 
rtnl_trylock() inside emac_tx_timeout_task() make sense?

Regards,
Ali