From patchwork Mon Nov 9 15:04:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zhang Qilong X-Patchwork-Id: 11891655 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 3C44E1130 for ; Mon, 9 Nov 2020 15:00:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26D172083B for ; Mon, 9 Nov 2020 15:00:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729905AbgKIPAp (ORCPT ); Mon, 9 Nov 2020 10:00:45 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:7506 "EHLO szxga05-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729940AbgKIPAp (ORCPT ); Mon, 9 Nov 2020 10:00:45 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4CVDgr5GkxzhfKR; Mon, 9 Nov 2020 23:00:24 +0800 (CST) Received: from huawei.com (10.175.127.227) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Mon, 9 Nov 2020 23:00:27 +0800 From: Zhang Qilong To: , , , CC: , Subject: [PATCH v2 1/2] PM: runtime: Add a general runtime get sync operation to deal with usage counter Date: Mon, 9 Nov 2020 23:04:15 +0800 Message-ID: <20201109150416.1877878-2-zhangqilong3@huawei.com> X-Mailer: git-send-email 2.25.4 In-Reply-To: <20201109150416.1877878-1-zhangqilong3@huawei.com> References: <20201109150416.1877878-1-zhangqilong3@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.127.227] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org In many case, we need to check return value of pm_runtime_get_sync, but it brings a trouble to the usage counter processing. Many callers forget to decrease the usage counter when it failed. It has been discussed a lot[0][1]. So we add a function to deal with the usage counter for better coding. [0]https://lkml.org/lkml/2020/6/14/88 [1]https://patchwork.ozlabs.org/project/linux-tegra/patch/20200520095148.10995-1-dinghao.liu@zju.edu.cn/ Signed-off-by: Zhang Qilong --- include/linux/pm_runtime.h | 30 ++++++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h index 4b708f4e8eed..6549ce764400 100644 --- a/include/linux/pm_runtime.h +++ b/include/linux/pm_runtime.h @@ -386,6 +386,36 @@ static inline int pm_runtime_get_sync(struct device *dev) return __pm_runtime_resume(dev, RPM_GET_PUT); } +/** + * pm_runtime_general_get - Bump up usage counter of a device and resume it. + * @dev: Target device. + * + * Increase runtime PM usage counter of @dev first, and carry out runtime-resume + * of it synchronously. If __pm_runtime_resume return negative value(device is in + * error state), we to need decrease the usage counter before it return. If + * __pm_runtime_resume return positive value, it means the runtime of device has + * already been in active state, and we let the new wrapper return zero instead. + * + * The possible return values of this function is zero or negative value. + * zero: + * - it means resume succeeed or runtime of device has already been active, the + * runtime PM usage counter of @dev remains incremented. + * negative: + * - it means failure and the runtime PM usage counter of @dev has been balanced. + */ +static inline int pm_runtime_general_get(struct device *dev) +{ + int ret = 0; + + ret = __pm_runtime_resume(dev, RPM_GET_PUT); + if (ret < 0) { + pm_runtime_put_noidle(dev); + return ret; + } + + return 0; +} + /** * pm_runtime_put - Drop device usage counter and queue up "idle check" if 0. * @dev: Target device.