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=-12.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 BF271C433B4 for ; Tue, 27 Apr 2021 07:03:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3B12611ED for ; Tue, 27 Apr 2021 07:03:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234615AbhD0HDr (ORCPT ); Tue, 27 Apr 2021 03:03:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:56916 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229547AbhD0HDp (ORCPT ); Tue, 27 Apr 2021 03:03:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 537C961159; Tue, 27 Apr 2021 07:03:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1619506982; bh=izivrDlVuNDG8rAEjfPQuF8j4WWF/Bepl7fmbRGNam0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LGqhJt0z5L3oHbMeWvaKxbgfcdzXj7KkduWLqyLKZTfWxvFNrQstpI1U5/d+Ca92L iyBuqEw1ZNfqiHsq6FtMILwOYxQgJCS7gPec4roam2rOI4P1RzZv+RLshy+eMKXK2P qBsYmLOEqiUetSKv9IFm7Wma6C3GRprkP3LBIINQzY1SivoCzsr9TXPYC1jh4XIA4Q PUq8Tqya6Kg1YjL+l9ZE4snc93muiruccuhd9OUWeg8gMSXdhk0p8OBxt4BQPY2LTF fcF09pT/C7wJRyt9jLtmKpYnYOAjJsW1PDYjaeDu4Y/cb2XGXi+L2CahdjNyIRcKas uL7dqPSeSbkPg== Date: Tue, 27 Apr 2021 09:02:58 +0200 From: Mauro Carvalho Chehab To: Sakari Ailus Cc: linuxarm@huawei.com, mauro.chehab@huawei.com, 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: <20210427090258.35627539@coco.lan> In-Reply-To: <20210426193223.78bd06f3@coco.lan> References: <34da940f76da6c1d61a193409164070f47243b64.1619191723.git.mchehab+huawei@kernel.org> <20210425185525.GS3@paasikivi.fi.intel.com> <20210426160151.61ac6ef2@coco.lan> <20210426140900.GW3@paasikivi.fi.intel.com> <20210426161659.7b979c44@coco.lan> <20210426142901.GX3@paasikivi.fi.intel.com> <20210426193223.78bd06f3@coco.lan> 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 Hi Sakari, Em Mon, 26 Apr 2021 19:32:23 +0200 Mauro Carvalho Chehab escreveu: > Em Mon, 26 Apr 2021 17:29:02 +0300 > Sakari Ailus escreveu: > > > On Mon, Apr 26, 2021 at 04:16:59PM +0200, Mauro Carvalho Chehab wrote: > > > Em Mon, 26 Apr 2021 17:09:00 +0300 > > > Sakari Ailus escreveu: > > > > > > > Hi Mauro, > > > > > > > > On Mon, Apr 26, 2021 at 04:01:51PM +0200, Mauro Carvalho Chehab wrote: > > > > > Em Sun, 25 Apr 2021 21:55:25 +0300 > > > > > Sakari Ailus escreveu: > > > > > ... > > > > > 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. > > > > > > > > Yeah, I agree. This code is one of the older parts the driver. > > > > > > > > Please add: > > > > > > > > Acked-by: Sakari Ailus > > > > > > > > The same goes for the other sensor driver patches in the set you cc'd me, > > > > i.e. patches 12, 15, 26, 28,32, 40, 45, 51, 53 and 55. > > > > > > It probably makes sense to address the suspend/resume -EAGAIN > > > return code on a separate patch series, before this one, as: > > > > > > 1. this is unrelated to this change; > > > 2. it is something that should be c/c to fixes. So, having it > > > before this series makes easier to apply there. > > > > Sounds good to me. If you can submit a patch, please add my ack. :-) > > Sure. I'll work on such patch series. I checked the files affected by those patches: 12, 15, 26, 28,32, 40, 45, 51, 53 and 55, e.g.: drivers/staging/media/atomisp/pci/atomisp_fops.c drivers/staging/media/ipu3/ipu3.c drivers/media/i2c/dw9714.c drivers/media/i2c/dw9807-vcm.c drivers/media/i2c/imx258.c drivers/media/i2c/ov13858.c drivers/media/i2c/ov8865.c drivers/media/i2c/tvp5150.c drivers/media/pci/intel/ipu3/ipu3-cio2-main.c I also double-checked the I2C drivers that use SET_SYSTEM_SLEEP_PM_OPS(). None of them are calling pm_runtime_* at suspend time, except for the ccs-core. So, I ended writing just a patch for ccs-core, to be applied before this /78 series. Thanks, Mauro