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=-17.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 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 3623FC433B4 for ; Mon, 26 Apr 2021 14:02:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EA30A61396 for ; Mon, 26 Apr 2021 14:02:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233690AbhDZOCl (ORCPT ); Mon, 26 Apr 2021 10:02:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:46522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231862AbhDZOCi (ORCPT ); Mon, 26 Apr 2021 10:02:38 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id EDA466101B; Mon, 26 Apr 2021 14:01:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619445716; bh=tzhLVdGbmmRdQPJ5eZRDCi1vw2kOOHnATu4ZWI3P46E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=U/oz00GpNcaxeqC+/8QTj7nLXoBGaWVVTeWcomZxD6ZJLXid8iFrLemb8qzTGTMyE lbIUP5mHp2kzEK+tAsIVJNqiKUHzV/4wUfv5ndrFY+RW6Zm6HSREFQ7GSBSZtRXywT sh5gJbO1i1H4YeH/AvHWI9Z5wsDwbRZWfPh/L5OC/xM5EJK5Flh8Dxklhf4OMIkfPd rS/ENnmlx7LGM+DwXIA9aM/camcCsLPRbwi+9NoqgBbE8cPpNRpp8X/R3492T/RLT6 PKUeEvnBhNc+jOdEZUe8KFMcDkUDLpYG0ZD2MmIIG0dkX2lOwCjXWs12IOXm/yQIg/ 8Rwc3v7kyelwQ== Date: Mon, 26 Apr 2021 16:01:51 +0200 From: Mauro Carvalho Chehab To: Sakari Ailus Cc: linuxarm@huawei.com, mauro.chehab@huawei.com, Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, linux-media@vger.kernel.org Subject: Re: [PATCH 25/78] media: i2c: ccs-core: use pm_runtime_resume_and_get() Message-ID: <20210426160151.61ac6ef2@coco.lan> In-Reply-To: <20210425185525.GS3@paasikivi.fi.intel.com> References: <34da940f76da6c1d61a193409164070f47243b64.1619191723.git.mchehab+huawei@kernel.org> <20210425185525.GS3@paasikivi.fi.intel.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Sun, 25 Apr 2021 21:55:25 +0300 Sakari Ailus escreveu: > Hi Mauro, > > Thanks for the patch. > > On Sat, Apr 24, 2021 at 08:44:35AM +0200, Mauro Carvalho Chehab wrote: > > Commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") > > added pm_runtime_resume_and_get() in order to automatically handle > > dev->power.usage_count decrement on errors. > > > > Use the new API, in order to cleanup the error check logic. > > > > Signed-off-by: Mauro Carvalho Chehab > > --- > > drivers/media/i2c/ccs/ccs-core.c | 11 +++++------ > > 1 file changed, 5 insertions(+), 6 deletions(-) > > > > diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c > > index 9dc3f45da3dc..1441ddcc9b35 100644 > > --- a/drivers/media/i2c/ccs/ccs-core.c > > +++ b/drivers/media/i2c/ccs/ccs-core.c > > @@ -1880,12 +1880,11 @@ static int ccs_pm_get_init(struct ccs_sensor *sensor) > > struct i2c_client *client = v4l2_get_subdevdata(&sensor->src->sd); > > int rval; > > > > - rval = pm_runtime_get_sync(&client->dev); > > - if (rval < 0) { > > - pm_runtime_put_noidle(&client->dev); > > - > > + rval = pm_runtime_resume_and_get(&client->dev); > > + if (rval < 0) > > return rval; > > - } else if (!rval) { > > + > > + if (!rval) { > > rval = v4l2_ctrl_handler_setup(&sensor->pixel_array-> > > ctrl_handler); > > if (rval) > > @@ -3089,7 +3088,7 @@ static int __maybe_unused ccs_suspend(struct device *dev) > > bool streaming = sensor->streaming; > > int rval; > > > > - rval = pm_runtime_get_sync(dev); > > + rval = pm_runtime_resume_and_get(dev); > > if (rval < 0) { > > pm_runtime_put_noidle(dev); > > You'll need to drop pm_runtime_put_noidle() here. OK! --- On a non-related issue at the same code, after the change, the suspend function will be: static int __maybe_unused ccs_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct v4l2_subdev *subdev = i2c_get_clientdata(client); struct ccs_sensor *sensor = to_ccs_sensor(subdev); bool streaming = sensor->streaming; int rval; rval = pm_runtime_resume_and_get(dev); if (rval < 0) return -EAGAIN; if (sensor->streaming) ccs_stop_streaming(sensor); /* save state for resume */ sensor->streaming = streaming; return 0; } Not sure if "return -EAGAIN" is the right thing here. I mean, the PM runtime core has two error conditions that are independent on whatever the PM callback would be doing[1]: if (dev->power.runtime_error) retval = -EINVAL; else if (dev->power.disable_depth > 0) retval = -EACCES; It would be very unlikely that trying to suspend again would solve those conditions. So, I guess that the right thing to do is to change the code to do, instead: static int __maybe_unused ccs_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct v4l2_subdev *subdev = i2c_get_clientdata(client); struct ccs_sensor *sensor = to_ccs_sensor(subdev); bool streaming = sensor->streaming; int rval; rval = pm_runtime_resume_and_get(dev); if (rval < 0) return rval; ... } [1] see rpm_resume() code at drivers/base/power/runtime.c. Thanks, Mauro