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,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 A9A61C43460 for ; Wed, 5 May 2021 12:35:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8E6AC613AA for ; Wed, 5 May 2021 12:35:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233497AbhEEMgx (ORCPT ); Wed, 5 May 2021 08:36:53 -0400 Received: from frasgout.his.huawei.com ([185.176.79.56]:3030 "EHLO frasgout.his.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229793AbhEEMgw (ORCPT ); Wed, 5 May 2021 08:36:52 -0400 Received: from fraeml702-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4FZwrn4Z44z70gJ2; Wed, 5 May 2021 20:24:57 +0800 (CST) Received: from lhreml710-chm.china.huawei.com (10.201.108.61) by fraeml702-chm.china.huawei.com (10.206.15.51) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Wed, 5 May 2021 14:35:54 +0200 Received: from localhost (10.52.120.138) 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; Wed, 5 May 2021 13:35:54 +0100 Date: Wed, 5 May 2021 13:34:15 +0100 From: Jonathan Cameron To: Mauro Carvalho Chehab CC: , , Fabien Dessenne , Mauro Carvalho Chehab , , Subject: Re: [PATCH 22/25] media: sti/bdisp: fix pm_runtime_get_sync() usage count Message-ID: <20210505133415.00006a2f@Huawei.com> In-Reply-To: References: 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: [10.52.120.138] X-ClientProxiedBy: lhreml725-chm.china.huawei.com (10.201.108.76) To lhreml710-chm.china.huawei.com (10.201.108.61) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 5 May 2021 11:42:12 +0200 Mauro Carvalho Chehab wrote: > The pm_runtime_get_sync() internally increments the > dev->power.usage_count without decrementing it, even on errors. > > The bdisp_start_streaming() doesn't take it into account, which > would unbalance PM usage counter at bdisp_stop_streaming(). > > The logic at bdisp_probe() is correct, but the best is to use > the same call along the driver. > > So, 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") > in order to properly decrement the usage counter, avoiding > a potential PM usage counter leak. > > Signed-off-by: Mauro Carvalho Chehab Reviewed-by: Jonathan Cameron > --- > drivers/media/platform/sti/bdisp/bdisp-v4l2.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/platform/sti/bdisp/bdisp-v4l2.c b/drivers/media/platform/sti/bdisp/bdisp-v4l2.c > index 060ca85f64d5..85288da9d2ae 100644 > --- a/drivers/media/platform/sti/bdisp/bdisp-v4l2.c > +++ b/drivers/media/platform/sti/bdisp/bdisp-v4l2.c > @@ -499,7 +499,7 @@ static int bdisp_start_streaming(struct vb2_queue *q, unsigned int count) > { > struct bdisp_ctx *ctx = q->drv_priv; > struct vb2_v4l2_buffer *buf; > - int ret = pm_runtime_get_sync(ctx->bdisp_dev->dev); > + int ret = pm_runtime_resume_and_get(ctx->bdisp_dev->dev); > > if (ret < 0) { > dev_err(ctx->bdisp_dev->dev, "failed to set runtime PM\n"); > @@ -1364,10 +1364,10 @@ static int bdisp_probe(struct platform_device *pdev) > > /* Power management */ > pm_runtime_enable(dev); > - ret = pm_runtime_get_sync(dev); > + ret = pm_runtime_resume_and_get(dev); > if (ret < 0) { > dev_err(dev, "failed to set PM\n"); > - goto err_pm; > + goto err_remove; > } > > /* Filters */ > @@ -1395,6 +1395,7 @@ static int bdisp_probe(struct platform_device *pdev) > bdisp_hw_free_filters(bdisp->dev); > err_pm: > pm_runtime_put(dev); > +err_remove: > bdisp_debugfs_remove(bdisp); > v4l2_device_unregister(&bdisp->v4l2_dev); > err_clk: