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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_2 autolearn=ham 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 21BC3C433ED for ; Fri, 30 Apr 2021 16:29:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E10E2613CE for ; Fri, 30 Apr 2021 16:29:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230081AbhD3Qak (ORCPT ); Fri, 30 Apr 2021 12:30:40 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:2958 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229821AbhD3Qak (ORCPT ); Fri, 30 Apr 2021 12:30:40 -0400 Received: from fraeml715-chm.china.huawei.com (unknown [172.18.147.207]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FWyLb22clz71fjS; Sat, 1 May 2021 00:21:59 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml715-chm.china.huawei.com (10.206.15.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 30 Apr 2021 18:29:50 +0200 Received: from localhost (10.52.124.90) by lhreml710-chm.china.huawei.com (10.201.108.61) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 30 Apr 2021 17:29:49 +0100 Date: Fri, 30 Apr 2021 17:28:15 +0100 From: Jonathan Cameron To: Mauro Carvalho Chehab CC: , , Jacopo Mondi , Mauro Carvalho Chehab , , , Subject: Re: [PATCH v4 12/79] media: renesas-ceu: Properly check for PM errors Message-ID: <20210430172815.00007111@Huawei.com> In-Reply-To: <70e2f612d1d3b7ad74fbfc5f90850f3874670fb2.1619621413.git.mchehab+huawei@kernel.org> References: <70e2f612d1d3b7ad74fbfc5f90850f3874670fb2.1619621413.git.mchehab+huawei@kernel.org> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.52.124.90] X-ClientProxiedBy: lhreml719-chm.china.huawei.com (10.201.108.70) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org On Wed, 28 Apr 2021 16:51:33 +0200 Mauro Carvalho Chehab wrote: > Right now, the driver just assumes that PM runtime resume > worked, but it may fail. > > Well, the pm_runtime_get_sync() internally increments the > dev->power.usage_count without decrementing it, even on errors. > > So, using it is tricky. Let's replace it by the new > pm_runtime_resume_and_get(), introduced by: > commit dd8088d5a896 ("PM: runtime: Add pm_runtime_resume_and_get to deal with usage counter") > and return an error if something bad happens. > > This should ensure that the PM runtime usage_count will be > properly decremented if an error happens at open time. > > Signed-off-by: Mauro Carvalho Chehab LGTM Reviewed-by: Jonathan Cameron > --- > drivers/media/platform/renesas-ceu.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/platform/renesas-ceu.c b/drivers/media/platform/renesas-ceu.c > index cd137101d41e..17f01b6e3fe0 100644 > --- a/drivers/media/platform/renesas-ceu.c > +++ b/drivers/media/platform/renesas-ceu.c > @@ -1099,10 +1099,10 @@ static int ceu_open(struct file *file) > > mutex_lock(&ceudev->mlock); > /* Causes soft-reset and sensor power on on first open */ > - pm_runtime_get_sync(ceudev->dev); > + ret = pm_runtime_resume_and_get(ceudev->dev); > mutex_unlock(&ceudev->mlock); > > - return 0; > + return ret; > } > > static int ceu_release(struct file *file)