From patchwork Mon Jul 16 23:45:35 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laurent Pinchart X-Patchwork-Id: 1202671 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id D054EE0038 for ; Mon, 16 Jul 2012 23:46:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751723Ab2GPXpd (ORCPT ); Mon, 16 Jul 2012 19:45:33 -0400 Received: from perceval.ideasonboard.com ([95.142.166.194]:42704 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751308Ab2GPXpc (ORCPT ); Mon, 16 Jul 2012 19:45:32 -0400 Received: from avalon.localnet (unknown [91.178.73.93]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 5672C7AAF; Tue, 17 Jul 2012 01:45:31 +0200 (CEST) From: Laurent Pinchart To: David Cohen Cc: Guennadi Liakhovetski , linux-media@vger.kernel.org Subject: Re: [PATCH v2 7/9] soc-camera: Continue the power off sequence if one of the steps fails Date: Tue, 17 Jul 2012 01:45:35 +0200 Message-ID: <11676269.DxxC5Mj13x@avalon> User-Agent: KMail/4.8.3 (Linux/3.3.8-gentoo; KDE/4.8.3; x86_64; ; ) In-Reply-To: <50034325.50006@linux.intel.com> References: <1341520728-2707-1-git-send-email-laurent.pinchart@ideasonboard.com> <1341520728-2707-8-git-send-email-laurent.pinchart@ideasonboard.com> <50034325.50006@linux.intel.com> MIME-Version: 1.0 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi David, Thank you for the review. On Monday 16 July 2012 01:24:37 David Cohen wrote: > On 07/05/2012 11:38 PM, Laurent Pinchart wrote: > > Powering off a device is a "best effort" task: failure to execute one of > > the steps should not prevent the next steps to be executed. For > > instance, an I2C communication error when putting the chip in stand-by > > mode should not prevent the more agressive next step of turning the > > chip's power supply off. > > > > Signed-off-by: Laurent Pinchart > > --- > > > > drivers/media/video/soc_camera.c | 9 +++------ > > 1 files changed, 3 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/media/video/soc_camera.c > > b/drivers/media/video/soc_camera.c index 55b981f..bbd518f 100644 > > --- a/drivers/media/video/soc_camera.c > > +++ b/drivers/media/video/soc_camera.c > > @@ -89,18 +89,15 @@ static int soc_camera_power_off(struct > > soc_camera_device *icd,> > > struct soc_camera_link *icl) > > { > > struct v4l2_subdev *sd = soc_camera_to_subdev(icd); > > - int ret = v4l2_subdev_call(sd, core, s_power, 0); > > + int ret; > > > > - if (ret < 0 && ret != -ENOIOCTLCMD && ret != -ENODEV) > > - return ret; > > + v4l2_subdev_call(sd, core, s_power, 0); > > Fair enough. I agree we should not prevent power off because of failure > in this step. But IMO we should not silently bypass it too. How about > an error message? I'll add that. > > if (icl->power) { > > > > ret = icl->power(icd->control, 0); > > > > - if (ret < 0) { > > + if (ret < 0) > > > > dev_err(icd->pdev, > > > > "Platform failed to power-off the camera.\n"); > > > > - return ret; > > - } > > > > } > > > > ret = regulator_bulk_disable(icl->num_regulators, > > One more comment. Should this function's return value being based fully > on last action? If any earlier error happened but this last step is > fine, IMO we should not return 0. Good point. What about this (on top of the current patch) ? diff --git a/drivers/media/video/soc_camera.c b/drivers/media/video/soc_camera.c index bbd518f..7bf21da 100644 --- a/drivers/media/video/soc_camera.c +++ b/drivers/media/video/soc_camera.c @@ -89,21 +89,30 @@ static int soc_camera_power_off(struct soc_camera_device *icd, struct soc_camera_link *icl) { struct v4l2_subdev *sd = soc_camera_to_subdev(icd); - int ret; + int ret = 0; + int err; - v4l2_subdev_call(sd, core, s_power, 0); + err = v4l2_subdev_call(sd, core, s_power, 0); + if (err < 0 && err != -ENOIOCTLCMD && err != -ENODEV) { + dev_err(icd->pdev, "Subdev failed to power-off the camera.\n"); + ret = err; + } if (icl->power) { - ret = icl->power(icd->control, 0); - if (ret < 0) + err = icl->power(icd->control, 0); + if (err < 0) { dev_err(icd->pdev, "Platform failed to power-off the camera.\n"); + ret = ret ? : err; + } } - ret = regulator_bulk_disable(icl->num_regulators, + err = regulator_bulk_disable(icl->num_regulators, icl->regulators); - if (ret < 0) + if (err < 0) { dev_err(icd->pdev, "Cannot disable regulators\n"); + ret = ret ? : err; + } return ret; }