Re: [PATCH net-next v5 7/8] net: bcmgenet: allow the MTU to be changed

[Jakub Kicinski]

On Tue, 13 Oct 2026 16:20:36 +0200 Nicolai Buchwitz wrote:
> +	ret = bcmgenet_init_dma(priv, true);
> +	if (ret) {
> +		/* Retry the size that was allocated a moment ago */
> +		WRITE_ONCE(dev->mtu, old_mtu);
> +		priv->rx_buf_len = bcmgenet_rx_buf_len(old_mtu);
> +		bcmgenet_set_mtu_regs(priv, old_mtu);
> +		if (bcmgenet_init_dma(priv, true)) {

This will fail under memory pressure leaving the device inoperable.

> +	priv->datapath_up = true;

Hallmark of a bad design