From patchwork Sat Jul 11 20:32:06 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Lunn X-Patchwork-Id: 1327388 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=lunn.ch Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4B41n44Y3Qz9sRN for ; Sun, 12 Jul 2020 06:32:40 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727942AbgGKUcj (ORCPT ); Sat, 11 Jul 2020 16:32:39 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:58822 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727021AbgGKUce (ORCPT ); Sat, 11 Jul 2020 16:32:34 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1juMAg-004eo3-6R; Sat, 11 Jul 2020 22:32:30 +0200 From: Andrew Lunn To: David Miller Cc: netdev , Vivien Didelot , Russell King , Chris Healy , Fugang Duan , Andrew Lunn Subject: [PATCH net-next 2/2] net: fec: Set max MTU size to allow the MTU to be changed Date: Sat, 11 Jul 2020 22:32:06 +0200 Message-Id: <20200711203206.1110108-3-andrew@lunn.ch> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200711203206.1110108-1-andrew@lunn.ch> References: <20200711203206.1110108-1-andrew@lunn.ch> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The FEC allocates 2K buffers, but looses some of it due to alignment. It can however support an MTU bigger than the default. This is particularly interesting when used in combination with Ethernet switches supporting DSA, which have extra headers. The DSA core will try to increase the MTU to support these extra headers. If the max size defaults to that of standard Ethernet we get a warning. By setting the max to what the driver actually supports, we avoid this warning. Signed-off-by: Andrew Lunn --- drivers/net/ethernet/freescale/fec_main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c index 9f80a33c5b16..8047dda947f2 100644 --- a/drivers/net/ethernet/freescale/fec_main.c +++ b/drivers/net/ethernet/freescale/fec_main.c @@ -3710,6 +3710,8 @@ fec_probe(struct platform_device *pdev) fec_enet_clk_enable(ndev, false); pinctrl_pm_select_sleep_state(&pdev->dev); + ndev->max_mtu = PKT_MAXBUF_SIZE - ETH_HLEN - ETH_FCS_LEN; + ret = register_netdev(ndev); if (ret) goto failed_register;