Subject: Re: [PATCH net-next v2 1/3] net/stmmac/dwxgmac: Modify DMA functions for future hardware

From: Jakub Kicinski <[email-masked]>
Date: Fri, 5 Jun 2026 19:02:10 -0700

On Wed, 3 Jun 2026 14:45:53 +0200 Larysa Zaremba wrote:
> > > Because dwxgmac2_set_mtl_tx_queue_weight() returns void and is invoked via
> > > the stmmac_do_void_callback() macro (which unconditionally returns 0), will
> > > this early return cause ETS qdisc queue weighting on higher queue indices
> > > to silently fail? 
> > > It appears userspace will receive a success code while the hardware is left
> > > unconfigured.
> > 
> > As talked in previous mailing, answer is yes, there will be error in dmesg,
> > but no fail, for very simple reason that we would need to rewrite A LOT to add
> > proper error handling.
> > I just hope that if user misconfigured this stuff they will read this error
> > and fix it rather than complain.
> 
> But previously those callbacks did not have any failure conditions, so I would 
> say that adding a message-only failure does constitute a minor regression.

+1, this feels a bit sloppy. The driver has some painful abstraction
layers but if we cut ourselves some slack because of that that'd be
basically encouraging shitty architectures.
-- 
pw-bot: cr