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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS 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 B4E7FC28CF6 for ; Wed, 1 Aug 2018 21:45:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A6F9208B4 for ; Wed, 1 Aug 2018 21:45:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=broadcom.com header.i=@broadcom.com header.b="T788MoqH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6A6F9208B4 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=broadcom.com 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 S1732495AbeHAXcx (ORCPT ); Wed, 1 Aug 2018 19:32:53 -0400 Received: from mail-qt0-f193.google.com ([209.85.216.193]:34071 "EHLO mail-qt0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731900AbeHAXcx (ORCPT ); Wed, 1 Aug 2018 19:32:53 -0400 Received: by mail-qt0-f193.google.com with SMTP id m13-v6so151856qth.1 for ; Wed, 01 Aug 2018 14:45:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=R8LoDlBgBzG0IhNTvlYK3b1w91hZxR7DIj5KJGZCT5s=; b=T788MoqHoWrO77BZIEit+XrWmKrcn/gRSJAtDl1MAqvXZPMPm59zZUbffN3IwE01Gd syBp0hfLez9MHFPG9QRPQKj88BzhAUESbwb/z3gdiL6ebj9nPrDroCAEmeOnPL0LLJ+y td5YoceaPPHbzfxFRRpxxk0faNjf0TCwTEOwo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=R8LoDlBgBzG0IhNTvlYK3b1w91hZxR7DIj5KJGZCT5s=; b=bS41H1Kjx/6Uc3rIt9nd5/i7z5kj/mOaSuEwi/cBWr/VkHCDzpYfqa5qpvPjbGzR/V 6wqN9TeE8PTLKT2g4DDsuwvqxITKKNCAnR7BwI5OHh5Z/ZlKDuQ9jJUx6uXo7fzPodtn BqD+1V6Y4sQOwag7wlHC1FFhG0JXHqE4Cad7FEi+vtgEWZSkxMsMx9kYPaw1kBv4CMQl zMY3If1VntJyvDP9QEKc07GZ3z2JxwvCenr7awdB/oHoeuIrtWQFLOBHT6cfz5zSepgS OSJN1LkFNfdfiaRhhadhplsSkTEUiCwit8ewRQtGDsxuXYSQfRyPvmizLIJq3LRHpGb2 uARQ== X-Gm-Message-State: AOUpUlHoDPcG296U7kmFmF0H/YyjUfWu7S2zhLo+Endp55SxVeLYaq/H C4UYBK2Ui6q9yQjLafyHJtJi1l/YfIx9/g== X-Google-Smtp-Source: AAOMgpcGAuX5/ozrgNIqVMs/4IPm9L+dOzTI2PZS7uF1XEi89gEtpV557LkF0OQRy87YhjehSQyk9g== X-Received: by 2002:aed:3c34:: with SMTP id t49-v6mr102888qte.404.1533159903065; Wed, 01 Aug 2018 14:45:03 -0700 (PDT) Received: from [10.136.4.147] ([192.19.228.250]) by smtp.gmail.com with ESMTPSA id 14-v6sm69965qty.57.2018.08.01.14.44.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 Aug 2018 14:45:02 -0700 (PDT) Subject: Re: [PATCH v3 7/8] net: phy: Add support to configure clock in Broadcom iProc mdio mux To: Andrew Lunn , Russell King - ARM Linux Cc: 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 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> <20180801202313.GH30658@n2100.armlinux.org.uk> <20180801203846.GE19257@lunn.ch> From: Arun Parameswaran Message-ID: <8133c1f0-addc-5c48-7a6a-44b0d106c425@broadcom.com> Date: Wed, 1 Aug 2018 14:45:22 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180801203846.GE19257@lunn.ch> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Andrew, Russell, On 18-08-01 01:38 PM, Andrew Lunn wrote: > On Wed, Aug 01, 2018 at 09:23:14PM +0100, Russell King - ARM Linux wrote: >> 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 > > That makes it hard. I added phy_optional_get() early on, when the > error cases were simple. Hopefully they remain simple... > > Andrew > I traced the devm_clk_get() and ran into various error codes, so I figured I should return error on all the other errors (like ENOMEM, EINVAL & EPROBE_DEFER) but 'ENOENT'. But, looking at the errors from Russell's email, it looks like I should look for both 'ENOENT' and 'EINVAL' and consider both these errors as 'clock not specified' ? Can I do something like this in the code for this patchset: md->core_clk = devm_clk_get(&pdev->dev, NULL); if (md->core_clk == ERR_PTR(-ENOENT) || md->core_clk == ERR_PTR(-EINVAL)) { /* clock is optional, without it the default * rate divider register values will be used */ md->core_clk = NULL; } else if (IS_ERR(md->core_clk)) { return PTR_ERR(md->core_clk); } else { rc = clk_prepare_enable(md->core_clk); ... } Thanks Arun