Re: [PATCH 2/3] net: ethernet: cortina: Count dropped frames as NAPI work

[Joe Damato <joe@dama.to>]

On Tue, Sep 01, 2026 at 07:04:56PM +0200, Linus Walleij wrote:
> The RX loop only consumes budget when it successfully delivers a frame.
> Error paths keep consuming descriptors without reducing the budget, so a
> stream of bad frames can process the entire receive ring in one poll.
> 
> Move the budget accounting to a common end-of-frame path. This counts
> each completed frame as NAPI work whether it was delivered or dropped,
> matching the behavior of the vendor driver.
> 
> Fixes: 4d5ae32f5e1e ("net: ethernet: Add a driver for Gemini gigabit ethernet")
> Assisted-by: LLM
> Signed-off-by: Linus Walleij <linusw@kernel.org>
> ---
>  drivers/net/ethernet/cortina/gemini.c | 30 +++++++++++++++++-------------
>  1 file changed, 17 insertions(+), 13 deletions(-)

[...]

> @@ -1575,27 +1579,27 @@ static int gmac_napi_poll(struct napi_struct *napi, int budget)
>  	struct gemini_ethernet_port *port = netdev_priv(napi->dev);
>  	struct gemini_ethernet *geth = port->geth;
>  	unsigned int freeq_threshold;
> -	unsigned int received;
> +	unsigned int work_done;
>  
>  	freeq_threshold = 1 << (geth->freeq_order - 1);
>  	u64_stats_update_begin(&port->rx_stats_syncp);
>  
> -	received = gmac_rx(napi->dev, budget);
> -	if (received < budget) {
> +	work_done = gmac_rx(napi->dev, budget);
> +	if (work_done < budget) {
>  		napi_gro_flush(napi, false);
> -		napi_complete_done(napi, received);
> +		napi_complete_done(napi, work_done);
>  		gmac_enable_rx_irq(napi->dev, 1);
>  		++port->rx_napi_exits;
>  	}

Hmm. I could be wrong, but I think the above code could be simplified by
calling napi_complete_done and letting it do the gro_flush? You can check the
return value and then optionally enable interrupts. That's what most other
drivers do, IIRC.