From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BD1BBC433E1 for ; Mon, 22 Mar 2021 23:39:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 84DEA619A9 for ; Mon, 22 Mar 2021 23:39:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230320AbhCVXjN (ORCPT ); Mon, 22 Mar 2021 19:39:13 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:41772 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230009AbhCVXil (ORCPT ); Mon, 22 Mar 2021 19:38:41 -0400 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1lOU7e-00CUJd-OG; Tue, 23 Mar 2021 00:38:10 +0100 Date: Tue, 23 Mar 2021 00:38:10 +0100 From: Andrew Lunn To: Cristian Ciocaltea Cc: "David S. Miller" , Jakub Kicinski , Rob Herring , Andreas =?iso-8859-1?Q?F=E4rber?= , Manivannan Sadhasivam , Philipp Zabel , netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-actions@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/3] net: ethernet: actions: Add Actions Semi Owl Ethernet MAC driver Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > +static void owl_emac_set_multicast(struct net_device *netdev, int count) > +{ > + struct owl_emac_priv *priv = netdev_priv(netdev); > + struct netdev_hw_addr *ha; > + int index = 0; > + > + if (count <= 0) { > + priv->mcaddr_list.count = 0; > + return; > + } > + > + netdev_for_each_mc_addr(ha, netdev) { > + if (!is_multicast_ether_addr(ha->addr)) > + continue; Is this possible? > + > + WARN_ON(index >= OWL_EMAC_MAX_MULTICAST_ADDRS); > + ether_addr_copy(priv->mcaddr_list.addrs[index++], ha->addr); > + } > + > + priv->mcaddr_list.count = index; > + > + owl_emac_setup_frame_xmit(priv); > +} > + > +static void owl_emac_ndo_set_rx_mode(struct net_device *netdev) > +{ > + struct owl_emac_priv *priv = netdev_priv(netdev); > + u32 status, val = 0; > + int mcast_count = 0; > + > + if (netdev->flags & IFF_PROMISC) { > + val = OWL_EMAC_BIT_MAC_CSR6_PR; > + } else if (netdev->flags & IFF_ALLMULTI) { > + val = OWL_EMAC_BIT_MAC_CSR6_PM; > + } else if (netdev->flags & IFF_MULTICAST) { > + mcast_count = netdev_mc_count(netdev); > + > + if (mcast_count > OWL_EMAC_MAX_MULTICAST_ADDRS) { > + val = OWL_EMAC_BIT_MAC_CSR6_PM; > + mcast_count = 0; > + } > + } > + > + spin_lock_bh(&priv->lock); > + > + /* Temporarily stop DMA TX & RX. */ > + status = owl_emac_dma_cmd_stop(priv); > + > + /* Update operation modes. */ > + owl_emac_reg_update(priv, OWL_EMAC_REG_MAC_CSR6, > + OWL_EMAC_BIT_MAC_CSR6_PR | OWL_EMAC_BIT_MAC_CSR6_PM, > + val); > + > + /* Restore DMA TX & RX status. */ > + owl_emac_dma_cmd_set(priv, status); > + > + spin_unlock_bh(&priv->lock); > + > + /* Set/reset multicast addr list. */ > + owl_emac_set_multicast(netdev, mcast_count); > +} I think this can be simplified. At least, you had me going around in circles a while trying to see if WARN_ON() could be triggered from user space. If you have more than OWL_EMAC_MAX_MULTICAST_ADDRS MC addresses, you go into promisc mode. Can you then skip calling owl_emac_set_multicast(), which appears not to do too much useful when passed 0? Andrew