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=-14.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 B9B60C433EF for ; Sun, 19 Sep 2021 09:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8EAF661074 for ; Sun, 19 Sep 2021 09:44:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237716AbhISJpW (ORCPT ); Sun, 19 Sep 2021 05:45:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237818AbhISJpQ (ORCPT ); Sun, 19 Sep 2021 05:45:16 -0400 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 68CCDC061574; Sun, 19 Sep 2021 02:43:46 -0700 (PDT) Received: by mail-pg1-x52f.google.com with SMTP id n18so14378973pgm.12; Sun, 19 Sep 2021 02:43:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=ujZYCN2hNIBT5RbdU8R3eOc6j6lEG3PQETpYdg9DbBc=; b=MRfUZHjikWvtbxL9OaHghlwj40Fx/p2cDFvuKXkLmqdBPDvOSgx9Rmhuayid1vNXcD GlGdc+shfLUDhFE4jaPnEWlCa/OZ9cQRpY8i9ewKdbC4V08O6D2INQvVvHFKlK1qMGNq Xw9niYzj5ddgEtVfkrOMt7NNQpNO6/pmhVtwzpMbtWYD/+FtkZjBWRUcLj30SfpUxTlF dZ4N/WQhGchhvzTBixOhZ0RSlz5+c3dqdBzUMQ891gcS6ukQGrUMfnlcWVrCNf6PJyU2 RQ5mKVGbGyCVcp5ugIv7nq36a31GaNsfnuMaCX+IFrwlOjSqcHq0Yn+Zuz8ca9EQ8CXf RQ1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; 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=ujZYCN2hNIBT5RbdU8R3eOc6j6lEG3PQETpYdg9DbBc=; b=MtAKbHGjJUEwxOzneet4gbgGLd6no3KD6WBp3DxHAqsioiKJpYeIrBjbCt4UT9GeSJ lxc5ekZBySuWMwRdjqtUdI2p8/ZdRvmq/bJyFdHsrjTnTCRFRs1xXjJhSH8gscb346AW 1yl6lT1Eur68KfMw3suIp/KMdX8xtHdq0WX4fgeK5mYriiTPggOHWN1L6IJh9QWp54HR KF9kpPY2DywgwwxyFhARinIBOLoFeomI+/4tkhJW6CfJ7EC0BAeZ1TeFUInUuH2Pi/Z9 ymZtLqY2XYx0WMakp12sLibJZMb2TX0b8vDXO3tjGDBvdi+saMcUefk7ydGS48XMOm4E 9dBg== X-Gm-Message-State: AOAM531tDdrw8f9IY7cH1pNKGSGBfc77S9lbbKDSY/F2YKJEmXBluUz5 5TsV9ks2THg+on5U5p65OqGFO2nkVj4= X-Google-Smtp-Source: ABdhPJxbbHzNmfgc5i6PcrHjAWEr1DMvwBIs+hDKpJBTdjeXbNpu+gig3MhSpK+FL8ySD6H3hcMnOw== X-Received: by 2002:a63:ce57:: with SMTP id r23mr18549344pgi.271.1632044625811; Sun, 19 Sep 2021 02:43:45 -0700 (PDT) Received: from [172.30.1.2] ([14.32.163.5]) by smtp.gmail.com with ESMTPSA id y80sm6403104pfb.196.2021.09.19.02.43.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 19 Sep 2021 02:43:45 -0700 (PDT) Subject: Re: [PATCH v1 4/4] PM / devfreq: tegra30: Check whether clk_round_rate() returns zero rate To: Dmitry Osipenko Cc: linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, Thierry Reding , Jonathan Hunter , Viresh Kumar , Nishanth Menon , MyungJoo Ham , Stephen Boyd , Kyungmin Park , Chanwoo Choi References: <20210912184458.17995-1-digetx@gmail.com> <20210912184458.17995-5-digetx@gmail.com> <9fa66405-883a-3653-eb5d-3cd7eee07a0a@gmail.com> <26d90b01-13d5-3bd8-da0a-b9ff61c7845a@gmail.com> From: Chanwoo Choi Message-ID: <4b5faca8-c0fc-e7bb-5a0b-c66714bc5f61@gmail.com> Date: Sun, 19 Sep 2021 18:43:41 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <26d90b01-13d5-3bd8-da0a-b9ff61c7845a@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 21. 9. 16. 오전 10:28, Dmitry Osipenko wrote: > 15.09.2021 21:31, Chanwoo Choi пишет: >> On 21. 9. 15. 오후 12:51, Chanwoo Choi wrote: >>> Hi, >>> >>> On 21. 9. 13. 오전 3:44, Dmitry Osipenko wrote: >>>> EMC clock is always-on and can't be zero. Check whether clk_round_rate() >>>> returns zero rate and error out if it does. It can return zero if clock >>>> tree isn't initialized properly. >>>> >>>> Signed-off-by: Dmitry Osipenko >>>> --- >>>>   drivers/devfreq/tegra30-devfreq.c | 4 ++-- >>>>   1 file changed, 2 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/drivers/devfreq/tegra30-devfreq.c >>>> b/drivers/devfreq/tegra30-devfreq.c >>>> index d83fdc2713ed..65ecf17a36f4 100644 >>>> --- a/drivers/devfreq/tegra30-devfreq.c >>>> +++ b/drivers/devfreq/tegra30-devfreq.c >>>> @@ -891,9 +891,9 @@ static int tegra_devfreq_probe(struct >>>> platform_device *pdev) >>>>           return err; >>>>       rate = clk_round_rate(tegra->emc_clock, ULONG_MAX); >>>> -    if (rate < 0) { >>>> +    if (rate <= 0) { >>>>           dev_err(&pdev->dev, "Failed to round clock rate: %ld\n", >>>> rate); >>>> -        return rate; >>>> +        return rate ?: -EINVAL; >> >> If rate is 0, It doesn't return and fall-through? even if print the >> error message. 'return rate ?: -EINVAL;' style is strange for me >> because it doesn't specify the 'return value' when rate is true. > > It's not clear to me what do you mean by "return and fall-through". > > It specifies the 'return value' when rate is true. It's a short form of > "rate ? rate : -EINVAL". I has not known this short form. Thanks for comment. I understand. -- Best Regards, Samsung Electronics Chanwoo Choi