Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754639AbdIHDQt (ORCPT ); Thu, 7 Sep 2017 23:16:49 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:33267 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754583AbdIHDQq (ORCPT ); Thu, 7 Sep 2017 23:16:46 -0400 X-Google-Smtp-Source: ADKCNb4s5JkZnfa2LMfQMY3USPxhbKnrV9ea6nIEJyxhFa8wALSykIj9FOOqAoExfb6Y4VmmSPawTA== Date: Thu, 7 Sep 2017 20:16:43 -0700 From: Eduardo Valentin To: Daniel Lezcano Cc: rui.zhang@intel.com, linux-pm@vger.kernel.org, kevin.wangtao@linaro.org, leo.yan@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH V2 06/13] thermal/drivers/hisi: Remove pointless lock Message-ID: <20170908031641.GD2755@localhost.localdomain> References: <1504554972-2624-1-git-send-email-daniel.lezcano@linaro.org> <1504554972-2624-6-git-send-email-daniel.lezcano@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1504554972-2624-6-git-send-email-daniel.lezcano@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1506 Lines: 40 On Mon, Sep 04, 2017 at 09:56:05PM +0200, Daniel Lezcano wrote: > The threaded interrupt inspect the sensors structure to look in the temp > threshold field, but this field is read-only in all the code, except in the > probe function before the threaded interrupt is set. In other words there > is not race window in the threaded interrupt when reading the field value. Sure? Not even if you have a userspace process read the zone temp via sysfs and the polling workqueue reading the temp too? > > Signed-off-by: Daniel Lezcano > Reviewed-by: Leo Yan > --- > drivers/thermal/hisi_thermal.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c > index f523197..9ec5f29 100644 > --- a/drivers/thermal/hisi_thermal.c > +++ b/drivers/thermal/hisi_thermal.c > @@ -221,14 +221,10 @@ static irqreturn_t hisi_thermal_alarm_irq(int irq, void *dev) > static irqreturn_t hisi_thermal_alarm_irq_thread(int irq, void *dev) > { > struct hisi_thermal_data *data = dev; > - struct hisi_thermal_sensor *sensor; > - > - mutex_lock(&data->thermal_lock); > - sensor = &data->sensors; > + struct hisi_thermal_sensor *sensor = &data->sensors; > > dev_crit(&data->pdev->dev, "THERMAL ALARM: T > %d\n", > sensor->thres_temp); > - mutex_unlock(&data->thermal_lock); > > thermal_zone_device_update(data->sensors.tzd, > THERMAL_EVENT_UNSPECIFIED); > -- > 2.7.4 >