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=-0.7 required=3.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_SIGNED,DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 C0B14C433DB for ; Tue, 23 Mar 2021 08:36:09 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 42A6961974 for ; Tue, 23 Mar 2021 08:36:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 42A6961974 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=wDO+MCbZZTDnch4tXRZdlPixfRJVuXYhNbWn9M+u6p4=; b=cy9X5AVq9YsZmJhjwEyi2xqfd xXz9NObPkQkFPu8E14xJeTVox5NCMKcJRgyLqvltJPhmelp4BotlnYdwjzU8usbT4nkKVEXBY6KcC zejp4F0/7ncy+PuP2Pm08avrBFfJfobVrCndjTHsN6rlMKJsov4ZB6Qc47tb+Mh1dYX9y5ThG8Yda YhS9jE87+3Bsa9n8poIElCWjP+mrCSYRtWxpQruqhTgT4nMMoMRZH8/bpCZLRu2mCRCFR8X/aCN/s NJ/CEzYF9efxtcT+qn7wZ+N8zjFas60XThsH70p3ob+vmckWQ9AnfWZdnY9rXz9qJcTEyFFVmwbhf CHFM6Gv1w==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lOcUa-00EKOO-Hd; Tue, 23 Mar 2021 08:34:24 +0000 Received: from mail-ej1-x62b.google.com ([2a00:1450:4864:20::62b]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lOcUR-00EKN1-1l; Tue, 23 Mar 2021 08:34:17 +0000 Received: by mail-ej1-x62b.google.com with SMTP id e14so7457716ejz.11; Tue, 23 Mar 2021 01:34:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=tmrrCrm7e1zSN6hwhjd5NWevnLXHS1M8CpySj+eKpTU=; b=i6IibXJALrk7pV6yxzodjehS744kAzduD3Vb7WZmwSP5Wfjse4HPjNc5vxlEJsc6MC ycR7DpDdCrUMM6xYKKheYVCZWwWXs/aNGQQnaT9BYPvN08m5Nm4221WqrA4jumQMmtG2 Tx3TWL+X9xN5AUhcpHhFoTAOm8Nz4tEnVgWpT3e/tr/bHem8+a+mBXVkecb4FxMO+m+c X8I2IwyK113CPOzoFn6FrHjWV+JqcymQjzxVzoEj39XUjew6SGwmT9X6OFDN6LZnj7D+ pYQRVpN25TE3gEdLy15uTewZ/rQ9UP8uBFtjnxYuvt+yRa4hX9UJ9S89vB1+9MjNeBHS YCVA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=tmrrCrm7e1zSN6hwhjd5NWevnLXHS1M8CpySj+eKpTU=; b=VqxzQbUgIxtsr0TWs6FPHAlpcFvxGRxgI5AXj8m7Yzq/zNCmJvzf/TdM+eZ2ihivgW hulQN47VwN5/pK6/9cIqtdhKdHDTktiT2cn3/KuCr81gjccBlz8cO0Qf2DJ1oZuD+onH /m4YVDAO0i8CCT9errO3ynT3s7GMAg1Qetv8mdlmzWprdeXyBcUVzGCKD6qk/0XWNjW6 73SknRk68hWDiwmvSDQcxHSd7gF2xC77rTIxQsIrOe244cYhu/BY+BdP8lrbzni0q6Qr VK7o+Ot6Wsfm7xIw95Xixd5HGeeKy+AhRVKAAwn8PpcaYXK4nWLo/o5M3fC66LeGdQSL X6uw== X-Gm-Message-State: AOAM5302IUsSSCuPACb4eRcJDJultuKEqhmDA4KvPCE6sePjvhT4RsT9 wfFZLaCOjJ8LNPhmzK07Eig= X-Google-Smtp-Source: ABdhPJwIALEKdLucqLbI6sSOHvuo1BJxTidEiRQ8Q5vk6hRRPsnBiTQnc0JOMtCv6ehQq48kd/ETyA== X-Received: by 2002:a17:906:3b48:: with SMTP id h8mr3758493ejf.261.1616488453142; Tue, 23 Mar 2021 01:34:13 -0700 (PDT) Received: from BV030612LT ([188.24.140.160]) by smtp.gmail.com with ESMTPSA id q16sm10729363ejd.15.2021.03.23.01.34.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Mar 2021 01:34:12 -0700 (PDT) Date: Tue, 23 Mar 2021 10:34:09 +0200 From: Cristian Ciocaltea To: Andrew Lunn 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: <20210323083409.GA1559969@BV030612LT> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210323_083415_402936_E3E9D9C6 X-CRM114-Status: GOOD ( 22.31 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Mar 23, 2021 at 12:38:10AM +0100, Andrew Lunn wrote: > > +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? I remember I've seen this in one of the drivers I have studied, but I'm not really sure it is actually necessary. I added it to be on the safe side.. > > + > > + 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? The main purpose of always calling owl_emac_set_multicast() is to ensure the size of the mcaddr_list is correctly updated (either set or reset). This prevents owl_emac_setup_frame_xmit() using obsolete data, when invoked from different contexts (i.e. MAC address changed). A conditional call involves splitting the mcaddr_list management logic (i.e. moving the 'reset' operation from the callee to the caller), which IMO would make the usage of a separate function less justified. Thanks, Cristi > > Andrew _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel