Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752452AbcDUM2V (ORCPT ); Thu, 21 Apr 2016 08:28:21 -0400 Received: from mga02.intel.com ([134.134.136.20]:29494 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751770AbcDUM2U (ORCPT ); Thu, 21 Apr 2016 08:28:20 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,512,1455004800"; d="scan'208";a="89283436" Message-ID: <1461241760.6620.315.camel@linux.intel.com> Subject: Re: [PATCH v3] i2c: designware-platdrv: fix unbalanced clk enable and prepare From: Andy Shevchenko To: Jisheng Zhang , jarkko.nikula@linux.intel.com, mika.westerberg@linux.intel.com, wsa@the-dreams.de Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Date: Thu, 21 Apr 2016 15:29:20 +0300 In-Reply-To: <1461237767-7928-1-git-send-email-jszhang@marvell.com> References: <1461237767-7928-1-git-send-email-jszhang@marvell.com> Organization: Intel Finland Oy Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.18.5.1-1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2578 Lines: 84 On Thu, 2016-04-21 at 19:22 +0800, Jisheng Zhang wrote: > If i2c_dw_probe() fails, we should disable and unprepare the clock, > otherwise the clock enable and prepare is left unbalanced. > > In dw_i2c_plat_remove(), we'd better to not rely on rpm to disable Sorry, didn't notice earlier rpm -> runtime PM > and unprepare the clock since CONFIG_PM may be disabled when > configuring the kernel. So we explicitly disable and unprepare the > clock in dw_i2c_plat_remove() rather than implicitly rely on > pm_runtime_put_sync(). To keep the device usage count balanced, we > call pm_runtime_put_noidle(() to decrease the usage count. (() -> () > > Signed-off-by: Jisheng Zhang I don't know if Wolfram wants you to send new version, and I dunno if others still have comments, but Patch is in a good shape, but I think we have to carefully check the runtime PM change. > --- > Since v2: >  - s/clk/clock >  - describe why use pm_runtime_put_noidle() > > Since v1: >  - fix commit msg: "not rely on rpm" rather than "rely on rpm" >  - call i2c_dw_plat_prepare_clk after pm_rumtime_disable() > >  drivers/i2c/busses/i2c-designware-platdrv.c | 16 ++++++++++------ >  1 file changed, 10 insertions(+), 6 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c > b/drivers/i2c/busses/i2c-designware-platdrv.c > index d656657..a771781 100644 > --- a/drivers/i2c/busses/i2c-designware-platdrv.c > +++ b/drivers/i2c/busses/i2c-designware-platdrv.c > @@ -253,8 +253,11 @@ static int dw_i2c_plat_probe(struct > platform_device *pdev) >   } >   >   r = i2c_dw_probe(dev); > - if (r && !dev->pm_runtime_disabled) > - pm_runtime_disable(&pdev->dev); > + if (r) { > + if (!dev->pm_runtime_disabled) > + pm_runtime_disable(&pdev->dev); > + i2c_dw_plat_prepare_clk(dev, false); > + } >   >   return r; >  } > @@ -264,15 +267,16 @@ static int dw_i2c_plat_remove(struct > platform_device *pdev) >   struct dw_i2c_dev *dev = platform_get_drvdata(pdev); >   >   pm_runtime_get_sync(&pdev->dev); > + pm_runtime_dont_use_autosuspend(&pdev->dev); > + if (!dev->pm_runtime_disabled) > + pm_runtime_disable(&pdev->dev); > + pm_runtime_put_noidle(&pdev->dev); >   >   i2c_del_adapter(&dev->adapter); >   >   i2c_dw_disable(dev); >   > - pm_runtime_dont_use_autosuspend(&pdev->dev); > - pm_runtime_put_sync(&pdev->dev); > - if (!dev->pm_runtime_disabled) > - pm_runtime_disable(&pdev->dev); > + i2c_dw_plat_prepare_clk(dev, false); >   >   return 0; >  } -- Andy Shevchenko Intel Finland Oy