Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753523AbdIDJRB (ORCPT ); Mon, 4 Sep 2017 05:17:01 -0400 Received: from mail-wm0-f48.google.com ([74.125.82.48]:37451 "EHLO mail-wm0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753445AbdIDJQ6 (ORCPT ); Mon, 4 Sep 2017 05:16:58 -0400 X-Google-Smtp-Source: ADKCNb7AKVhC9MECHny8GolVGj0YZ7WzBS8oqcb008wkGNm2Y0ivBBFLM8SsX8uxxHfZqBRd3cqk2g== Subject: Re: [PATCH 08/13] thermal/drivers/hisi: Fix configuration register setting To: Leo Yan Cc: rui.zhang@intel.com, edubezval@gmail.com, linux-pm@vger.kernel.org, kevin.wangtao@linaro.org, open list References: <1504082857-21702-1-git-send-email-daniel.lezcano@linaro.org> <1504082857-21702-8-git-send-email-daniel.lezcano@linaro.org> <20170902025426.GA3841@leoy-linaro> <20170904005825.GH3841@leoy-linaro> From: Daniel Lezcano Message-ID: <1d06208d-714c-efcd-13ae-fd1117bf0f74@linaro.org> Date: Mon, 4 Sep 2017 11:16:55 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170904005825.GH3841@leoy-linaro> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2782 Lines: 72 On 04/09/2017 02:58, Leo Yan wrote: > On Sat, Sep 02, 2017 at 10:34:34AM +0200, Daniel Lezcano wrote: >> On 02/09/2017 04:54, Leo Yan wrote: >>> On Wed, Aug 30, 2017 at 10:47:32AM +0200, Daniel Lezcano wrote: >>>> The TEMP0_CFG configuration register contains different field to set up the >>>> temperature controller. However in the code, nothing prevents a setup to >>>> overwrite the previous one: eg. writing the hdak value overwrites the sensor >>>> selection, the sensor selection overwrites the hdak value. >>>> >>>> In order to prevent such thing, use a regmap-like mechanism by reading the >>>> value before, set the corresponding bits and write the result. >>>> >>>> Signed-off-by: Daniel Lezcano >>>> --- >>>> drivers/thermal/hisi_thermal.c | 30 +++++++++++++++++++++++++----- >>>> 1 file changed, 25 insertions(+), 5 deletions(-) >>>> >>>> diff --git a/drivers/thermal/hisi_thermal.c b/drivers/thermal/hisi_thermal.c >>>> index d77a938..3e03908 100644 >>>> --- a/drivers/thermal/hisi_thermal.c >>>> +++ b/drivers/thermal/hisi_thermal.c >>>> @@ -132,19 +132,39 @@ static inline void hisi_thermal_enable(void __iomem *addr, int value) >>>> writel(value, addr + TEMP0_EN); >>>> } >>>> >>>> -static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor) >>>> +static inline int hisi_thermal_get_temperature(void __iomem *addr) >>>> { >>>> - writel((sensor << 12), addr + TEMP0_CFG); >>>> + return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE)); >>>> } >>>> >>>> -static inline int hisi_thermal_get_temperature(void __iomem *addr) >>>> +/* >>>> + * Temperature configuration register - Sensor selection >>>> + * >>>> + * Bits [19:12] >>>> + * >>>> + * 0x0: local sensor (default) >>>> + * 0x1: remote sensor 1 (ACPU cluster 1) >>>> + * 0x2: remote sensor 2 (ACPU cluster 0) >>>> + * 0x3: remote sensor 3 (G3D) >>>> + */ >>>> +static inline void hisi_thermal_sensor_select(void __iomem *addr, int sensor) >>>> { >>>> - return hisi_thermal_step_to_temp(readl(addr + TEMP0_VALUE)); >>>> + writel(readl(addr + TEMP0_CFG) | (sensor << 12), addr + TEMP0_CFG); >>> >>> nitpick: maybe it's better to firstly clear related bits and then set >>> value? >> >> Sorry, I don't get the comment. Can you elaborate ? > > Sure, here I am bit concern there the mixing old bits value and new > setting bits. My suggested code likes below: > > u32 val; > > val = readl(addr + TEMP0_CFG); > val &= ~0xF000; > val |= (sensor << 12); > writel(val, addr + TEMP0_CFG); Oh, yes. Good catch. -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog