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=-0.8 required=3.0 tests=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 09AE0C54FD0 for ; Mon, 20 Apr 2020 16:11:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB6D12074F for ; Mon, 20 Apr 2020 16:11:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=walle.cc header.i=@walle.cc header.b="Gft4E8gY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728017AbgDTQLZ (ORCPT ); Mon, 20 Apr 2020 12:11:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37222 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1725958AbgDTQLZ (ORCPT ); Mon, 20 Apr 2020 12:11:25 -0400 Received: from ssl.serverraum.org (ssl.serverraum.org [IPv6:2a01:4f8:151:8464::1:2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E72ADC061A0C; Mon, 20 Apr 2020 09:11:24 -0700 (PDT) Received: from ssl.serverraum.org (web.serverraum.org [172.16.0.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ssl.serverraum.org (Postfix) with ESMTPSA id 24DB823058; Mon, 20 Apr 2020 18:11:23 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=walle.cc; s=mail2016061301; t=1587399083; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JV6/yxI0hnc0gvSbIatDYRHmoDSkrGEsV3XUSagw0bk=; b=Gft4E8gYE1Lgsbzo3T45DiSRrqtW8EXgO1MzjtcCpkpzeNmTcz9ooabT2uU5w+5DEq1jiB Fm2CW2M+hAkXy/yB6/MppZvOKIVGP+qyL8twG3E2QEaWi6pe5VB8nmJZ+has2k0UFwuWs5 zegzfvshTGmk6r02tUYBRwmwFvYHTbU= MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Date: Mon, 20 Apr 2020 18:11:22 +0200 From: Michael Walle To: Andrew Lunn Cc: linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Jean Delvare , Guenter Roeck , Florian Fainelli , Heiner Kallweit , Russell King , "David S . Miller" Subject: Re: [PATCH net-next 3/3] net: phy: bcm54140: add hwmon support In-Reply-To: <20200420153625.GA917792@lunn.ch> References: <20200417201338.GI785713@lunn.ch> <84679226df03bdd8060cb95761724d3a@walle.cc> <20200417212829.GJ785713@lunn.ch> <4f3ff33f78472f547212f87f75a37b66@walle.cc> <20200419162928.GL836632@lunn.ch> <20200419170547.GO836632@lunn.ch> <0f7ea4522a76f977f3aa3a80dd62201d@walle.cc> <20200419215549.GR836632@lunn.ch> <75428c5faab7fc656051ab227663e6e6@walle.cc> <20200420153625.GA917792@lunn.ch> Message-ID: <00e8c608daac498623643e8f769f80a6@walle.cc> X-Sender: michael@walle.cc User-Agent: Roundcube Webmail/1.3.10 X-Spamd-Bar: + X-Rspamd-Server: web X-Rspamd-Queue-Id: 24DB823058 X-Spamd-Result: default: False [1.40 / 15.00]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TAGGED_RCPT(0.00)[]; MIME_GOOD(-0.10)[text/plain]; DKIM_SIGNED(0.00)[]; RCPT_COUNT_SEVEN(0.00)[10]; NEURAL_HAM(-0.00)[-0.970]; RCVD_COUNT_ZERO(0.00)[0]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_CC(0.00)[vger.kernel.org,suse.com,roeck-us.net,gmail.com,armlinux.org.uk,davemloft.net]; MID_RHS_MATCH_FROM(0.00)[]; SUSPICIOUS_RECIPS(1.50)[] Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 2020-04-20 17:36, schrieb Andrew Lunn: >> Ok I see, but what locking do you have in mind? We could have >> something >> like >> >> __phy_package_write(struct phy_device *dev, u32 regnum, u16 val) >> { >> return __mdiobus_write(phydev->mdio.bus, phydev->shared->addr, >> regnum, val); >> } >> >> and its phy_package_write() equivalent. But that would just be >> convenience functions, nothing where you actually help the user with >> locking. Am I missing something? > > In general, drivers should not be using __foo functions. We want > drivers to make use of phy_package_write() which would do the bus > locking. Look at a typical PHY driver. There is no locking what so > ever. Just lots of phy_read() and phy write(). The locking is done by > the core and so should be correct. Ok, but for example the BCM54140 uses indirect register access and thus need to lock the mdio bus itself in which case I need the __funcs. >> > > > Get the core to do reference counting on the structure? >> > > > Add helpers phy_read_shared(), phy_write_shared(), etc, which does >> > > > MDIO accesses on the base device, taking care of the locking. >> > > > >> > > The "base" access is another thing, I guess, which has nothing to do >> > > with the shared structure. >> > > >> > I'm making the assumption that all global addresses are at the base >> > address. If we don't want to make that assumption, we need the change >> > the API above so you pass a cookie, and all PHYs need to use the same >> > cookie to identify the package. >> >> how would a phy driver deduce a common cookie? And how would that be a >> difference to using a PHY address. > > For a cookie, i don't care how the driver decides on the cookie. The > core never uses it, other than comparing cookies to combine individual > PHYs into a package. It could be a PHY address. It could be the PHY > address where the global registers are. Or it could be anything else. > >> > Maybe base is the wrong name, since MSCC can have the base as the high >> > address of the four, not the low? >> >> I'd say it might be any of the four addresses as long as it is the >> same >> across the PHYs in the same package. And in that case you can also >> have >> the phy_package_read/write() functions. > > Yes. That is the semantics which is think is most useful. But then we > don't have a cookie, the value has real significance, and we need to > document what is should mean. Agreed. I will post a RFC shortly. -michael