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=-6.7 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 B4AA2C3A5A2 for ; Tue, 20 Aug 2019 00:05:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 89D6722CF6 for ; Tue, 20 Aug 2019 00:05:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="W2ZnE/px" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728351AbfHTAFE (ORCPT ); Mon, 19 Aug 2019 20:05:04 -0400 Received: from mail-qt1-f193.google.com ([209.85.160.193]:35174 "EHLO mail-qt1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728642AbfHTAFD (ORCPT ); Mon, 19 Aug 2019 20:05:03 -0400 Received: by mail-qt1-f193.google.com with SMTP id u34so4006073qte.2 for ; Mon, 19 Aug 2019 17:05:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=EqawCVMNR5ggkVvM3Y8TbC/GggOP05ogNA2z4zWjBzA=; b=W2ZnE/pxltTX4kXiXH96rp142zmXmi2sD4mi6KTNLHIp3seAnOcVlhN0dqf6iMWn4x RXqhV3hcByajFyP9UJKzVpbTZspbLawweQJWhwe3YVlJ9g6iW/KPDZSemRIltIlOeQd+ D4/1LhNRdtgfjVEKONKun8bNqwtRTvgHPDMkXzVPA0J2HEQXzUN6X9+92PixFL6TLsS7 w4BHqL/BJNcqkSmJdFS9cLDFS3btD9pC/aDz8ko6Nyg3I7POzUYsEM+U4ZGMWiJP0nM4 8po2viFqcGLQLq9Y1lRGyNujerL0eRYMcYunMrGhW5kYC79Y93PRe8Kc2lL8EtKmxnM1 MPAA== 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:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=EqawCVMNR5ggkVvM3Y8TbC/GggOP05ogNA2z4zWjBzA=; b=CM7bHNC/sRtouHfz2Bxdw3USFF4glukEP6z8uuhXpWU0F7xbf8eStPdHCrq4GxcYsu ncMsEi9ZvFkuAeh8Wm43RCSMrgMYeDsBYeW7DaVEBPrD28ytV1+SXBBJw8Tr1d49DhS5 FZ1sC8YJ5rpitc7Agdj+RhmM4Q7hm8zLMt9fG34/inssNZsaT9RBba8pCujFgfoKIPhp fZLsK2TwTkXat6YDwOSiC+S4mm2El4gm0a918XRZri3iRpOD1G0L5Mqthmj2Q+ToOJGU KwbR4FGXDh0Qn0ZQhP9gxgo/eh5fiZwFOFfugwhb2oygqu6wK9QUPKOlbO5W+6VaOuR4 aDKQ== X-Gm-Message-State: APjAAAVQK2dd9wz9x8mOHMFPhZJ3xn82H1MDTVDoaOyKtv4b6DqnidiD u/NFV9kbYPHzu7SBvolTgqOoMg== X-Google-Smtp-Source: APXvYqwSt09bYAD/GaUVUI3fSb7OlzA8CcLokwjOvHc1e2U7D7S/CCp818w1Esqb0twyjrhfoLDxUw== X-Received: by 2002:a0c:b209:: with SMTP id x9mr2784510qvd.217.1566259502266; Mon, 19 Aug 2019 17:05:02 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id o27sm7646908qkm.37.2019.08.19.17.05.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 19 Aug 2019 17:05:02 -0700 (PDT) Date: Mon, 19 Aug 2019 17:04:53 -0700 From: Jakub Kicinski To: Thomas Bogendoerfer Cc: Jonathan Corbet , Ralf Baechle , Paul Burton , James Hogan , Dmitry Torokhov , Lee Jones , "David S. Miller" , Srinivas Kandagatla , Alessandro Zummo , Alexandre Belloni , Greg Kroah-Hartman , Jiri Slaby , Evgeniy Polyakov , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org, linux-input@vger.kernel.org, netdev@vger.kernel.org, linux-rtc@vger.kernel.org, linux-serial@vger.kernel.org Subject: Re: [PATCH v5 11/17] net: sgi: ioc3-eth: no need to stop queue set_multicast_list Message-ID: <20190819170440.37ff18d4@cakuba.netronome.com> In-Reply-To: <20190819163144.3478-12-tbogendoerfer@suse.de> References: <20190819163144.3478-1-tbogendoerfer@suse.de> <20190819163144.3478-12-tbogendoerfer@suse.de> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On Mon, 19 Aug 2019 18:31:34 +0200, Thomas Bogendoerfer wrote: > netif_stop_queue()/netif_wake_qeue() aren't needed for changing > multicast filters. Use spinlocks instead for proper protection > of private struct. >=20 > Signed-off-by: Thomas Bogendoerfer > --- > drivers/net/ethernet/sgi/ioc3-eth.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) >=20 > diff --git a/drivers/net/ethernet/sgi/ioc3-eth.c b/drivers/net/ethernet/s= gi/ioc3-eth.c > index d862f28887f9..7f85a3bfef14 100644 > --- a/drivers/net/ethernet/sgi/ioc3-eth.c > +++ b/drivers/net/ethernet/sgi/ioc3-eth.c > @@ -1542,8 +1542,7 @@ static void ioc3_set_multicast_list(struct net_devi= ce *dev) > struct netdev_hw_addr *ha; > u64 ehar =3D 0; > =20 > - netif_stop_queue(dev); /* Lock out others. */ > - > + spin_lock_irq(&ip->ioc3_lock); What does this lock protect? =F0=9F=A4=94 No question that stopping TX queu= es makes little sense, but this function is only called from ndo_set_rx_mode(), so with rtnl_lock held.=20 I thought it may protect ip->emcr, but that one is accessed with no locking from the ioc3_timer() -> ioc3_setup_duplex() path.. > if (dev->flags & IFF_PROMISC) { /* Set promiscuous. */ > ip->emcr |=3D EMCR_PROMISC; > writel(ip->emcr, ®s->emcr); > @@ -1572,7 +1571,7 @@ static void ioc3_set_multicast_list(struct net_devi= ce *dev) > writel(ip->ehar_l, ®s->ehar_l); > } > =20 > - netif_wake_queue(dev); /* Let us get going again. */ > + spin_unlock_irq(&ip->ioc3_lock); > } > =20 > module_pci_driver(ioc3_driver);