Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751454AbdILJWq (ORCPT ); Tue, 12 Sep 2017 05:22:46 -0400 Received: from lelnx194.ext.ti.com ([198.47.27.80]:49087 "EHLO lelnx194.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751419AbdILJWl (ORCPT ); Tue, 12 Sep 2017 05:22:41 -0400 Subject: Re: [PATCH v4 1/2] i2c: davinci: Add PM Runtime Support To: Baolin Wang CC: Franklin S Cooper Jr , Wolfram Sang , Rob Herring , , , , LKML , , , References: <20170911201145.31257-1-fcooper@ti.com> <20170911201145.31257-2-fcooper@ti.com> <021a99bb-3670-fff5-6835-b14d28827929@ti.com> From: Sekhar Nori Message-ID: Date: Tue, 12 Sep 2017 14:52:02 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1036 Lines: 26 On Tuesday 12 September 2017 02:44 PM, Baolin Wang wrote: > Hi, > > On 12 September 2017 at 16:48, Sekhar Nori wrote: >> On Tuesday 12 September 2017 07:28 AM, Baolin Wang wrote: >>>> @@ -802,13 +821,24 @@ static int davinci_i2c_probe(struct platform_device *pdev) >>>> dev->clk = devm_clk_get(&pdev->dev, NULL); >>>> if (IS_ERR(dev->clk)) >>>> return PTR_ERR(dev->clk); >>>> - clk_prepare_enable(dev->clk); >> >>> You removed clk enable here, I think it can not work if we did not >>> open CONFIG_PM macro. I think you should keep clk enable here, and set >> >> What do you mean by "open CONFIG_PM macro" ? > > If you did not open CONFIG_PM macro, then the pm_runtime_xxx() will be > dummy functions, but now the i2c driver can not work since you did not > enable clock, right? Ah, okay. I am not sure thats a concern on platforms on which this driver is used. Without PM runtime support, most likely the platforms will not boot and multiple drivers will fail. Thanks, Sekhar