From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Lezcano Subject: Re: [PATCH 02/14] thermal: exynos: Propagate error value from tmu_read() Date: Mon, 16 Apr 2018 14:41:48 +0200 Message-ID: <22d7f063-9a69-78cf-e0fd-2043e187244e@linaro.org> References: <1523873525-23718-1-git-send-email-b.zolnierkie@samsung.com> <1523873525-23718-3-git-send-email-b.zolnierkie@samsung.com> <39e461aa-2a60-f3cf-d116-fc7e97f9da2e@linaro.org> <6993557.YT37RIp4lG@amdc3058> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <6993557.YT37RIp4lG@amdc3058> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Bartlomiej Zolnierkiewicz Cc: Eduardo Valentin , Zhang Rui , Krzysztof Kozlowski , Kukjin Kim , linux-samsung-soc@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, Marek Szyprowski List-Id: linux-pm@vger.kernel.org On 16/04/2018 14:35, Bartlomiej Zolnierkiewicz wrote: > On Monday, April 16, 2018 02:16:56 PM Daniel Lezcano wrote: >> On 16/04/2018 12:11, Bartlomiej Zolnierkiewicz wrote: >>> From: Marek Szyprowski >>> >>> tmu_read() in case of Exynos4210 might return error for out of bound >>> values. Current code ignores such value, what leads to reporting critical >>> temperature value. Add proper error code propagation to exynos_get_temp() >>> function. >> >> For me the comment in the function exynos4210_tmu_read >> >> /* "temp_code" should range between 75 and 175 */ >> >> ... is strange. I would double check this assertion before dealing with >> the error value. > > static int exynos4210_tmu_read(struct exynos_tmu_data *data) > { > int ret = readb(data->base + EXYNOS_TMU_REG_CURRENT_TEMP); > > /* "temp_code" should range between 75 and 175 */ > return (ret < 75 || ret > 175) ? -ENODATA : ret; > } > But I don't get why it *should* ? Shouldn't be the same with the 4412, it seems having the same sensor, no? > The value returned by Exynos4210 hardware should be > 75 && < 175 and > it is later used as the "temp_code" parameter for code_to_temp(): > > static int code_to_temp(struct exynos_tmu_data *data, u16 temp_code) > { > if (data->cal_type == TYPE_ONE_POINT_TRIMMING) > return temp_code - data->temp_error1 + EXYNOS_FIRST_POINT_TRIM; > > return (temp_code - data->temp_error1) * > (EXYNOS_SECOND_POINT_TRIM - EXYNOS_FIRST_POINT_TRIM) / > (data->temp_error2 - data->temp_error1) + > EXYNOS_FIRST_POINT_TRIM; > } > > so after the current fix the code finally matches the comment. > >>> Signed-off-by: Marek Szyprowski >>> CC: stable@vger.kernel.org # v4.6+ >>> Signed-off-by: Bartlomiej Zolnierkiewicz >>> --- >>> drivers/thermal/samsung/exynos_tmu.c | 9 +++++++-- >>> 1 file changed, 7 insertions(+), 2 deletions(-) >>> >>> diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c >>> index 986cbd0..ac83f72 100644 >>> --- a/drivers/thermal/samsung/exynos_tmu.c >>> +++ b/drivers/thermal/samsung/exynos_tmu.c >>> @@ -892,6 +892,7 @@ static void exynos7_tmu_control(struct platform_device *pdev, bool on) >>> static int exynos_get_temp(void *p, int *temp) >>> { >>> struct exynos_tmu_data *data = p; >>> + int value, ret = 0; >>> >>> if (!data || !data->tmu_read || !data->enabled) >>> return -EINVAL; >>> @@ -899,12 +900,16 @@ static int exynos_get_temp(void *p, int *temp) >>> mutex_lock(&data->lock); >>> clk_enable(data->clk); >>> >>> - *temp = code_to_temp(data, data->tmu_read(data)) * MCELSIUS; >>> + value = data->tmu_read(data); >>> + if (value < 0) >>> + ret = value; >>> + else >>> + *temp = code_to_temp(data, value) * MCELSIUS; >>> >>> clk_disable(data->clk); >>> mutex_unlock(&data->lock); >>> >>> - return 0; >>> + return ret; >>> } >>> >>> #ifdef CONFIG_THERMAL_EMULATION > > Best regards, > -- > Bartlomiej Zolnierkiewicz > Samsung R&D Institute Poland > Samsung Electronics > -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog