lkml.org 
[lkml]   [2018]   [Apr]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 02/14] thermal: exynos: Propagate error value from tmu_read()
From
Date
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 <m.szyprowski@samsung.com>
>>>
>>> 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 <m.szyprowski@samsung.com>
>>> CC: stable@vger.kernel.org # v4.6+
>>> Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
>>> ---
>>> 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
>


--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

\
 
 \ /
  Last update: 2018-04-16 14:42    [W:0.040 / U:2.588 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site