Re: [v5,net-next,6/8] bng_en: Add support to handle AGG events

[Jakub Kicinski <kuba@kernel.org>]

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---
bng_en: Add support to handle AGG events

This patch adds AGG event handling in the RX path to receive packet data
on AGG rings, enabling Jumbo and HDS functionality.

> diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_txrx.c b/drivers/net/ethernet/broadcom/bnge/bnge_txrx.c
> index dffb8c17babe..d6c8557fcb19 100644
> --- a/drivers/net/ethernet/broadcom/bnge/bnge_txrx.c
> +++ b/drivers/net/ethernet/broadcom/bnge/bnge_txrx.c

[ ... ]

> @@ -284,14 +487,25 @@ static int bnge_rx_pkt(struct bnge_net *bn, struct bnge_cp_ring_info *cpr,
>  	if (len <= bn->rx_copybreak) {
>  		skb = bnge_copy_skb(bnapi, data_ptr, len, dma_addr);
>  		bnge_reuse_rx_data(rxr, cons, data);
> -		if (!skb)
> +		if (!skb) {
> +			if (agg_bufs)
> +				bnge_reuse_rx_agg_bufs(cpr, cp_cons, 0,
> +						       agg_bufs);
>  			goto oom_next_rx;
> +		}
>  	} else {
>  		skb = bnge_rx_skb(bn, rxr, cons, data, data_ptr, dma_addr, len);
>  		if (!skb)
>  			goto oom_next_rx;
>  	}

In the copy path (small packets), when bnge_copy_skb() returns NULL, the code
properly calls bnge_reuse_rx_agg_bufs() to recycle the AGG buffers. However,
in the large packet path (else branch), when bnge_rx_skb() returns NULL, are
the AGG buffers being leaked? At this point the completion ring consumer has
already been advanced past the AGG completions by bnge_agg_bufs_valid(), but
without calling bnge_reuse_rx_agg_bufs() the AGG ring producer won't be
updated with replacement buffers.

Should the large packet path also reuse AGG buffers on allocation failure,
similar to the copy path?
-- 
pw-bot: cr