Subject: Re: [PATCH net-next] net: stmmac: enable RPS and RBU interrupts

From: Jakub Kicinski <[email-masked]>
Date: Mon, 13 Apr 2026 13:50:18 -0700

On Mon, 13 Apr 2026 19:49:46 +0100 Russell King (Oracle) wrote:
> > Firing interrupts when Rx fill ring runs dry (which IIUC this patches
> > dies?) is not a good idea.  
> 
> Well, I'm thinking that at least on some platforms, such as the Jetson
> Xavier NX, unless a different solution can be found, we need the RBU
> interrupt to fire off a reset of the stmmac IP when this happens to
> reduce the PAUSE frame flood on the network.
> 
> If we can't do that, then I think stmmac on these platforms needs to be
> marked with CONFIG_BROKEN because right now there doesn't seem to be any
> other viable solution.
> 
> My intention with this patch is merely to start collecting the already
> existing statistics so other users can start seeing whether they are
> hitting the same or similar problem. If we're not prepared to do that,
> then we should delete the useless statistics from ethtool -S, but I
> suspect they're now part of the UAPI, even though without this patch
> they will remain stedfastly stuck at zero.

Understood, thanks for the extra context. And the statistic we are
talking about is rx_buf_unav_irq ?