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=-2.4 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham 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 DF5EFC46463 for ; Wed, 1 Aug 2018 20:23:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9C6AB208A4 for ; Wed, 1 Aug 2018 20:23:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="D038rJL1" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9C6AB208A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732258AbeHAWLA (ORCPT ); Wed, 1 Aug 2018 18:11:00 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:44768 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728918AbeHAWLA (ORCPT ); Wed, 1 Aug 2018 18:11:00 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2014; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=AnQvRTHKIZj5HsT/xeNJWWXxGJBb5wQji5HEUtSnPhU=; b=D038rJL1jsni08C+C+rjBSLQH NcgMLUjDe0E/SzcPDVsj+Jg1NgmPSfNXO2Z3fA6vBiKLRojgx9AHGf18MCUVBLiR9Pa+MDsJnImXj osmsT/+Gw8ZIrjt3WaTcotayTeW9+jtm3l5FSNyl3PAMHM236ij7QBU257aXacqVGsSSI=; Received: from n2100.armlinux.org.uk ([fd8f:7570:feb6:1:214:fdff:fe10:4f86]:48555) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1fkxeQ-0005Pz-KA; Wed, 01 Aug 2018 21:23:18 +0100 Received: from linux by n2100.armlinux.org.uk with local (Exim 4.90_1) (envelope-from ) id 1fkxeN-0000DC-PJ; Wed, 01 Aug 2018 21:23:15 +0100 Date: Wed, 1 Aug 2018 21:23:14 +0100 From: Russell King - ARM Linux To: Andrew Lunn Cc: Arun Parameswaran , Florian Fainelli , "David S. Miller" , Rob Herring , Mark Rutland , Ray Jui , Scott Branden , Catalin Marinas , Will Deacon , netdev@vger.kernel.org, bcm-kernel-feedback-list@broadcom.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org Subject: Re: [PATCH v3 7/8] net: phy: Add support to configure clock in Broadcom iProc mdio mux Message-ID: <20180801202313.GH30658@n2100.armlinux.org.uk> References: <1533146186-8374-1-git-send-email-arun.parameswaran@broadcom.com> <1533146186-8374-8-git-send-email-arun.parameswaran@broadcom.com> <0cc6db4f-7008-0ad3-58d7-9e93060f152f@gmail.com> <20180801184659.GG30658@n2100.armlinux.org.uk> <9af7e7a3-54d4-8802-f64a-fc4f9c49c8b9@broadcom.com> <20180801200712.GD19257@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180801200712.GD19257@lunn.ch> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 01, 2018 at 10:07:12PM +0200, Andrew Lunn wrote: > You might want to consider adding clk_optional_get() and > devm_clk_optional_get(). I think there's attempts to add such APIs but I don't think it's trivial - it seems to require a _lot_ of discussion. I think part of that is because of the quirky use of error codes. If you look at clk_get(), it calls __of_clk_get_by_name() which returns: -ENOENT if DT is disabled -ENOENT if the device has no DT node -EPROBE_DEFER if the lookup in DT succeeds but there's no registered clock -EINVAL if the device has a DT node but the lookup of the name failed (in otherwords, the optional clock was omitted) -ENOENT if the clocks = property has not enough clocks for the clock-names property -ENOMEM if we fail to allocate the clk -ENOENT if __clk_get() fails or any other error code returned via of_clk_provider's ->get() method. The use of -EINVAL, one of the most common error codes, makes it difficult to be sure that the clock is not specified in DT. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 13.8Mbps down 630kbps up According to speedtest.net: 13Mbps down 490kbps up