From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chanwoo Choi Subject: Re: [PATCH v1] PM / devfreq: exynos-ppmu : Handle return value of clk_prepare_enable Date: Tue, 23 May 2017 18:41:59 +0900 Message-ID: <592403E7.8060906@samsung.com> References: <1495191364-16015-1-git-send-email-arvind.yadav.cs@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Return-path: Received: from mailout3.samsung.com ([203.254.224.33]:41741 "EHLO mailout3.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932938AbdEWJmL (ORCPT ); Tue, 23 May 2017 05:42:11 -0400 In-reply-to: <1495191364-16015-1-git-send-email-arvind.yadav.cs@gmail.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Arvind Yadav , myungjoo.ham@samsung.com, kyungmin.park@samsung.com, krzk@kernel.org, kgene@kernel.org, javier@osg.samsung.com Cc: linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-kernel@vger.kernel.org On 2017년 05월 19일 19:56, Arvind Yadav wrote: > clk_prepare_enable() can fail here and we must check its return value. > > Signed-off-by: Arvind Yadav > --- > drivers/devfreq/event/exynos-ppmu.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/devfreq/event/exynos-ppmu.c b/drivers/devfreq/event/exynos-ppmu.c > index 9b73509..8f6537a 100644 > --- a/drivers/devfreq/event/exynos-ppmu.c > +++ b/drivers/devfreq/event/exynos-ppmu.c > @@ -648,7 +648,11 @@ static int exynos_ppmu_probe(struct platform_device *pdev) > dev_name(&pdev->dev), desc[i].name); > } > > - clk_prepare_enable(info->ppmu.clk); > + ret = clk_prepare_enable(info->ppmu.clk); > + if (ret) { > + dev_err(&pdev->dev, "failed to prepare ppmu clock\n"); > + return ret; > + } You're right. But, actually, some ppmu device-tree node doesn't include the clock information because exynos clk driver don't support the clock for some ppmu devices. Until now, the clock of ppmu devices are default on state. Before applying this patch, exynos clock driver have to support the ppmu's clock and then add the clock information to the device tree of ppmu devices. > > return 0; > } > -- Best Regards, Chanwoo Choi Samsung Electronics