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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F338C433F5 for ; Wed, 23 Mar 2022 11:54:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244012AbiCWLz6 (ORCPT ); Wed, 23 Mar 2022 07:55:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33892 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232988AbiCWLz4 (ORCPT ); Wed, 23 Mar 2022 07:55:56 -0400 Received: from mail-ej1-x632.google.com (mail-ej1-x632.google.com [IPv6:2a00:1450:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58D84762A0; Wed, 23 Mar 2022 04:54:23 -0700 (PDT) Received: by mail-ej1-x632.google.com with SMTP id r13so2325490ejd.5; Wed, 23 Mar 2022 04:54:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=tjXHN/eiBOH25O5STfPTfLcMinZ5HpozLUsy3qwmmWQ=; b=In1lSLjOxNHM4lD+mv/8ysYHAWkl7ETBHGwMnp4xudlx8mi44elGLdb08B5eEJSRlu k+iECO8zs1svCZSfH4zbgyfFRAvnMe3vyv6q82h6/+/IXlukfE2oLslpiPBYzHaXtdkj kaLB+YrriT+JdvU/D3xm7ZTyiuPei5ti+aDRpHp+B1f7CWoQQ0QauEUpOqYkiMe+fkQy mD67albiSCRCVe0v1H3qySwvrUJsTgaRmiYcs1P5gXkIX1jRxChiFmcyN1ZWi06TxHRs 64AnXEgUCSupTx+TEEBR/YUY227lWtixDt2APmAM7LPtMh/O/CepNNQlzPCYj4kfV1zH fk7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=tjXHN/eiBOH25O5STfPTfLcMinZ5HpozLUsy3qwmmWQ=; b=LMrLBUHU/2ro4kkADgW/FnDc80EzZ3jLe4gFfwLSq3sMoeD1V4KiKEvRhxUBxIa3se +HQjEcwkTK6uxU/F1YKNRc8TiH2orYW3baqD1MMx/+eNgAr3kxg9qsQiktUMxBqoh8NM ryrKmk626xJhcxxSvnWTVPI0KGK7PViNARACbOHRZbw8Z/0tBNz0nDOSsJ2Ste7+Favq SqmxYHJ0LVGGl8WbT46/T19zf4+M0YdnWZlewKOX+l+ONp71wYsV6XvsT4Nd7IyukD56 Dmcob1kuV6QQkg4X5fk9iyZai4qvlkTZ78kE44/3vJ6Cpu5HPolJclPPkDzQtim/+HH9 lh9A== X-Gm-Message-State: AOAM532v0QcAhW/yEZBt//BlLv6PZiL8gneqFARNubzOnTfnyq5Zm3M7 //YN3Styd3VOp8K3zz9liXc= X-Google-Smtp-Source: ABdhPJzQdK6GZGqgS6tUs7KA2VUiibYqbOoA4gUyryiq0os00EyiyyvnXylRtnBUGjSvy1PZNlmCnQ== X-Received: by 2002:a17:906:c211:b0:6ce:e221:4c21 with SMTP id d17-20020a170906c21100b006cee2214c21mr30817095ejz.691.1648036461593; Wed, 23 Mar 2022 04:54:21 -0700 (PDT) Received: from skbuf ([188.26.57.45]) by smtp.gmail.com with ESMTPSA id j17-20020a05640211d100b00419357a2647sm5517586edw.25.2022.03.23.04.54.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Mar 2022 04:54:20 -0700 (PDT) Date: Wed, 23 Mar 2022 13:54:19 +0200 From: Vladimir Oltean To: Hans Schultz Cc: Andrew Lunn , davem@davemloft.net, kuba@kernel.org, netdev@vger.kernel.org, Vivien Didelot , Florian Fainelli , Jiri Pirko , Ivan Vecera , Roopa Prabhu , Nikolay Aleksandrov , Daniel Borkmann , Ido Schimmel , linux-kernel@vger.kernel.org, bridge@lists.linux-foundation.org Subject: Re: [PATCH net-next 3/3] net: dsa: mv88e6xxx: mac-auth/MAB implementation Message-ID: <20220323115419.svxnbcqqd7pyargn@skbuf> References: <20220318121400.sdc4guu5m4auwoej@skbuf> <86pmmjieyl.fsf@gmail.com> <20220318131943.hc7z52beztqlzwfq@skbuf> <86a6dixnd2.fsf@gmail.com> <20220322110806.kbdb362jf6pbtqaf@skbuf> <86fsn90ye8.fsf@gmail.com> <20220323101643.kum3nuqctunakcfo@skbuf> <864k3p5437.fsf@gmail.com> <20220323112116.q6shx2g4r23ungtc@skbuf> <86tuboao8o.fsf@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <86tuboao8o.fsf@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 23, 2022 at 12:43:03PM +0100, Hans Schultz wrote: > On ons, mar 23, 2022 at 13:21, Vladimir Oltean wrote: > > On Wed, Mar 23, 2022 at 11:57:16AM +0100, Hans Schultz wrote: > >> >> >> Another issue I see, is that there is a deadlock or similar issue when > >> >> >> receiving violations and running 'bridge fdb show' (it seemed that > >> >> >> member violations also caused this, but not sure yet...), as the unit > >> >> >> freezes, not to return... > >> >> > > >> >> > Have you enabled lockdep, debug atomic sleep, detect hung tasks, things > >> >> > like that? > >> >> > >> >> I have now determined that it is the rtnl_lock() that causes the > >> >> "deadlock". The doit() in rtnetlink.c is under rtnl_lock() and is what > >> >> takes care of getting the fdb entries when running 'bridge fdb show'. In > >> >> principle there should be no problem with this, but I don't know if some > >> >> interrupt queue is getting jammed as they are blocked from rtnetlink.c? > >> > > >> > Sorry, I forgot to respond yesterday to this. > >> > By any chance do you maybe have an AB/BA lock inversion, where from the > >> > ATU interrupt handler you do mv88e6xxx_reg_lock() -> rtnl_lock(), while > >> > from the port_fdb_dump() handler you do rtnl_lock() -> mv88e6xxx_reg_lock()? > >> > >> If I release the mv88e6xxx_reg_lock() before calling the handler, I need > >> to get it again for the mv88e6xxx_g1_atu_loadpurge() call at least. But > >> maybe the vtu_walk also needs the mv88e6xxx_reg_lock()? > >> I could also just release the mv88e6xxx_reg_lock() before the > >> call_switchdev_notifiers() call and reacquire it immediately after? > > > > The cleanest way to go about this would be to have the call_switchdev_notifiers() > > portion of the ATU interrupt handling at the very end of mv88e6xxx_g1_atu_prob_irq_thread_fn(), > > with no hardware access needed, and therefore no reg_lock() held. > > So something like? > mv88e6xxx_reg_unlock(chip); > rtnl_lock(); > err = call_switchdev_notifiers(SWITCHDEV_FDB_ADD_TO_BRIDGE, brport, &info.info, NULL); > rtnl_unlock(); > mv88e6xxx_reg_lock(chip); No, call_switchdev_notifiers() should be the very end, no reg_lock() afterwards. Do all the hardware handling you need, populate some variables to denote that you need to notify switchdev, and if you do, lock the rtnetlink mutex and do it.