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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 D3562C43461 for ; Tue, 1 Sep 2020 14:43:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2AD2215A4 for ; Tue, 1 Sep 2020 14:43:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="OA/2WXHY"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="VfTHIMCq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728388AbgIAOnI (ORCPT ); Tue, 1 Sep 2020 10:43:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728114AbgIAOQo (ORCPT ); Tue, 1 Sep 2020 10:16:44 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 14C28C061247; Tue, 1 Sep 2020 07:05:46 -0700 (PDT) From: Kurt Kanzenbach DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1598969144; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Z8QqyLda18GvzgzEa2BZRAqbRhiaUAxD4HcskwEK9y8=; b=OA/2WXHYfEL1UR/++jUzmCJejoAGIwlRpnMjkUSVgubq1FeRHr3OfZ9USQ1gE/CI5PT7Lj RQoIowDNkgN2P3pGTSOfIn/h1ejWaWrGDqhrIiJRW8d2O63VzqJ3Zv27hezntXkpSjpwUo mzXh2yi8rhhOx7j//aop9Z2O4794QHgiG6XvfTUhXZ+3mLcD2JdGee4KzM+hUfvshbu383 9re5Ckx1XS2hN9v0blaNStaXIjoZ5QeC9vzCGYVMPiuaVJqoDSSKw7Snx3Y+9B3/01cqNI MPtCGDjI+6cboSqfFLsZtHFgP6DKpc+QKFYLNPnT09e9HoEuWyYgH8O6Wx8GWg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1598969144; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=Z8QqyLda18GvzgzEa2BZRAqbRhiaUAxD4HcskwEK9y8=; b=VfTHIMCqtnFBoB0HPkuNE5jEiWNFnb6IXieWGVDnItFZKuERS7C5XshV7FxiY73RqYCouS SEgC49JeOGSoU0Cg== To: Vladimir Oltean Cc: Andrew Lunn , Vivien Didelot , Florian Fainelli , "David S. Miller" , Jakub Kicinski , netdev@vger.kernel.org, Rob Herring , devicetree@vger.kernel.org, Sebastian Andrzej Siewior , Richard Cochran , Kamil Alkhouri , ilias.apalodimas@linaro.org Subject: Re: [PATCH v4 2/7] net: dsa: Add DSA driver for Hirschmann Hellcreek switches In-Reply-To: <20200901134020.53vob6fis5af7nig@skbuf> References: <20200901125014.17801-1-kurt@linutronix.de> <20200901125014.17801-3-kurt@linutronix.de> <20200901134020.53vob6fis5af7nig@skbuf> Date: Tue, 01 Sep 2020 16:05:42 +0200 Message-ID: <87y2ltegnd.fsf@kurt> MIME-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org --=-=-= Content-Type: text/plain Hi Vladimir, On Tue Sep 01 2020, Vladimir Oltean wrote: > Hi Kurt, > > On Tue, Sep 01, 2020 at 02:50:09PM +0200, Kurt Kanzenbach wrote: [snip] >> +struct hellcreek { >> + const struct hellcreek_platform_data *pdata; >> + struct device *dev; >> + struct dsa_switch *ds; >> + struct hellcreek_port *ports; >> + struct mutex reg_lock; /* Switch IP register lock */ > > Pardon me asking, but I went back through the previous review comments > and I didn't see this being asked. It was asked multiple times, why there was a spinlock without interrupts being registered (see e.g. [1], [2]). I've used the spinlock variant, because the previously used hrtimers act like interrupts. As there are no timers anymore, there's no need for spinlocks and mutexes can be used. Florian Fainelli also asked if the reg lock can be removed completely. See below. > > What is the register lock protecting against, exactly? A lot of the register operations work by: * Select port, priority, vlan or counter * Configure it These sequences have to be atomic. That's what I wanted to ensure. Thanks, Kurt [1] - https://lkml.kernel.org/netdev/def49ff6-72fe-7ca0-9e00-863c314c1c3d@gmail.com/ [2] - https://lkml.kernel.org/netdev/20200624130318.GD7247@localhost/ --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEooWgvezyxHPhdEojeSpbgcuY8KYFAl9OVTYACgkQeSpbgcuY 8KZR9A//fUpNGkg2ivJeRvLXtvr4FbLG0ASFeE+pyc9dVBWa1RY+yP6H0fpOP9jR jlPqYVUlqxtiqlwHOd8GJ/PbnBlmKHcdf8BKnbM75fffeJjZm3Y+cl+CFJwJXkGe sKWFxGzQVbNmUsblEUWVOpuiU8XRRD8RjPCxMBW8FC5bVbhMKK1Fw7AT5K5M2e+d J3hhEa3qHsIqTSQhcb27N5Z94C6k9oKcRpkyTECngcX1IfNqcit6+OY7h5u4lqLz RVva3j1+tQJk7TgDWG+emcY5T7dpmnC2EgquPh3fs/peF1rfNswO2QqleFM8NHkI 1nHanLeutnkIrs5sGPHU5VM9Cb3ctnLIAQh/VpB5cUdAXfDSN/qJvlTo/ATN4rBM 3eL9dslrMt1dBXMteI4YMBj/CMHnQOP2HE0V2AXgAs4MRUn5ZWPInap/MCUMCWQC L0sOgb4Ye5k8uJH8dNS5j+sPqI6oeRBeTyZixLe9uTLdbH74o7nGpN4TGlQvpO04 OZ2vvDwoyRKVnYqsbYySZo7b6phqK5nUmDzzZRuGZKW9b/q0WWxCbJYgIjSBUVhU h/JrGFrnZ2uQ6B/VhbS0E5moFHob92uItlwFVl9tH81jn64cDg2Z4gI2E9WUNve6 enD+VGtnu4+BLbZ4a6wM6mmO9m2GdXaId6sKBQzs4nVvDC4AOHk= =Ww3M -----END PGP SIGNATURE----- --=-=-=--