Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754530AbdDDMTJ (ORCPT ); Tue, 4 Apr 2017 08:19:09 -0400 Received: from bastet.se.axis.com ([195.60.68.11]:51860 "EHLO bastet.se.axis.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752889AbdDDMTG (ORCPT ); Tue, 4 Apr 2017 08:19:06 -0400 From: Niklas Cassel To: , , , CC: , , Niklas Cassel Subject: [PATCH net-next] net: stmmac: allow changing the MTU while the interface is running Date: Tue, 4 Apr 2017 14:18:54 +0200 Message-ID: <20170404121854.606-1-niklass@axis.com> X-Mailer: git-send-email 2.11.0 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.0.5.60] X-ClientProxiedBy: XBOX04.axis.com (10.0.5.18) To XBOX02.axis.com (10.0.5.16) X-TM-AS-GCONF: 00 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1639 Lines: 50 From: Niklas Cassel Setting ethtool ops for stmmac is only allowed when the interface is up. Setting MTU (a netdev op) for stmmac is only allowed when the interface is down. It seems that the only reason why MTU cannot be changed when running is that we have not bothered to implement a nice way to dealloc/alloc the descriptor rings. To make it less confusing for the user, call ndo_stop() and ndo_open() from ndo_change_mtu(). This is not a nice way to dealloc/alloc the descriptor rings, since it will announce that the interface is being brought down/up to user space, but there are several other drivers doing it this way, and it is arguably better than just returning -EBUSY. Signed-off-by: Niklas Cassel --- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index c1c63197ff73..fd268dc0df02 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -3109,17 +3109,15 @@ static void stmmac_set_rx_mode(struct net_device *dev) */ static int stmmac_change_mtu(struct net_device *dev, int new_mtu) { - struct stmmac_priv *priv = netdev_priv(dev); - - if (netif_running(dev)) { - netdev_err(priv->dev, "must be stopped to change its MTU\n"); - return -EBUSY; - } - dev->mtu = new_mtu; netdev_update_features(dev); + if (netif_running(dev)) { + stmmac_release(dev); + stmmac_open(dev); + } + return 0; } -- 2.11.0