Subject: Re: [net-next PATCH] net: ethernet: stmicro: stmmac: permit MTU change with interface up

From: Ansuel Smith <[email-masked]>
Date: Thu, 16 Jun 2022 14:04:03 +0200

On Wed, Jun 15, 2022 at 07:55:07PM -0700, Jakub Kicinski wrote:
> On Wed, 15 Jun 2022 00:41:41 +0200 Christian 'Ansuel' Marangi wrote:
> > +	if (netif_running(dev)) {
> > +		netdev_dbg(priv->dev, "restarting interface to change its MTU\n");
> > +		stmmac_release(dev);
> > +
> > +		stmmac_open(dev);
> > +		stmmac_set_filter(priv, priv->hw, dev);
> 
> What if stmmac_open() fails because the memory is low or is fragmented?
> 
> You'd need to invest more effort into this change and try to allocate
> all the resources before shutting the device down.

Well what I'm doing here is following what is done with other similar
function in stmmac. For example the reinit_queues and reinit_ringparam
doesn't do such check.

But ok you are right, will see a good solution to change stmmac_open to
preallocate the buffers.

-- 
	Ansuel