Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751770AbdH3ItW (ORCPT ); Wed, 30 Aug 2017 04:49:22 -0400 Received: from mail-wr0-f179.google.com ([209.85.128.179]:38412 "EHLO mail-wr0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751622AbdH3ItE (ORCPT ); Wed, 30 Aug 2017 04:49:04 -0400 From: Daniel Lezcano To: rui.zhang@intel.com, edubezval@gmail.com Cc: daniel.lezcano@linaro.org, linux-pm@vger.kernel.org, kevin.wangtao@linaro.org, leo.yan@linaro.org, linux-kernel@vger.kernel.org (open list) Subject: [PATCH 13/13] thermal/drivers/hisi: Remove mutex_lock in the code Date: Wed, 30 Aug 2017 10:47:37 +0200 Message-Id: <1504082857-21702-13-git-send-email-daniel.lezcano@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1504082857-21702-1-git-send-email-daniel.lezcano@linaro.org> References: <1504082857-21702-1-git-send-email-daniel.lezcano@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1945 Lines: 59 The mutex is used to protect against writes in the configuration register. That happens at probe time, with no possible race yet. Then when the module is unloaded and at suspend/resume. When the module is unloaded, it is an userspace operation, thus via a process. Suspending the system goes through the freezer to suspend all the tasks synchronously before continuing. So it is not possible to hit the suspend ops in this driver while we are unloading it. The resume is the same situation than the probe. In other words, even if there are several places where we write the configuration register, there is no situation where we can write it at the same time, so far as I can judge Signed-off-by: Daniel Lezcano --- drivers/thermal/hisi_thermal.c | 6 ------ 1 file changed, 6 deletions(-) diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c index b1b086ab..b9e8ee2 100644 --- a/drivers/thermal/hisi_thermal.c +++ b/drivers/thermal/hisi_thermal.c @@ -51,7 +51,6 @@ struct hisi_thermal_sensor { }; struct hisi_thermal_data { - struct mutex thermal_lock; /* protects register data */ struct platform_device *pdev; struct clk *clk; struct hisi_thermal_sensor sensor; @@ -196,14 +195,10 @@ static inline void hisi_thermal_hdak_set(void __iomem *addr, int value) static void hisi_thermal_disable_sensor(struct hisi_thermal_data *data) { - mutex_lock(&data->thermal_lock); - /* disable sensor module */ hisi_thermal_enable(data->regs, 0); hisi_thermal_alarm_enable(data->regs, 0); hisi_thermal_reset_enable(data->regs, 0); - - mutex_unlock(&data->thermal_lock); } static int hisi_thermal_get_temp(void *__data, int *temp) @@ -340,7 +335,6 @@ static int hisi_thermal_probe(struct platform_device *pdev) if (!data) return -ENOMEM; - mutex_init(&data->thermal_lock); data->pdev = pdev; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); -- 2.7.4