Re: [PATCH v2 2/2] platform/x86: dell-ddv: Fix temperature scaling

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 2/18/23 12:53, Armin Wolf wrote:
> After using the built-in UEFI hardware diagnostics to compare
> the measured battery temperature, i noticed that the temperature
> is actually expressed in tenth degree kelvin, similar to the
> SBS-Data standard. For example, a value of 2992 is displayed as
> 26 degrees celsius.
> Fix the scaling so that the correct values are being displayed.
> 
> Tested on a Dell Inspiron 3505.
> 
> Fixes: a77272c16041 ("platform/x86: dell: Add new dell-wmi-ddv driver")
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>

Thanks, I've applied this patch to my review-hans branch:
https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

I'll rebase that branch once 6.3-rc1 is out and then push the rebased
patch to the fixes branch and include it in my next 6.3 fixes pull-req
to Linus.

Regards,

Hans



> ---
> Changes in v2:
> - Avoid unnecessary rounding
> ---
>  drivers/platform/x86/dell/dell-wmi-ddv.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/platform/x86/dell/dell-wmi-ddv.c b/drivers/platform/x86/dell/dell-wmi-ddv.c
> index eff4e9649faf..2750dee99c3e 100644
> --- a/drivers/platform/x86/dell/dell-wmi-ddv.c
> +++ b/drivers/platform/x86/dell/dell-wmi-ddv.c
> @@ -17,7 +17,6 @@
>  #include <linux/kernel.h>
>  #include <linux/hwmon.h>
>  #include <linux/kstrtox.h>
> -#include <linux/math.h>
>  #include <linux/math64.h>
>  #include <linux/module.h>
>  #include <linux/mutex.h>
> @@ -665,7 +664,8 @@ static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char
>  	if (ret < 0)
>  		return ret;
> 
> -	return sysfs_emit(buf, "%d\n", DIV_ROUND_CLOSEST(value, 10));
> +	/* Use 2731 instead of 2731.5 to avoid unnecessary rounding */
> +	return sysfs_emit(buf, "%d\n", value - 2731);
>  }
> 
>  static ssize_t eppid_show(struct device *dev, struct device_attribute *attr, char *buf)
> --
> 2.30.2
>