Re: [PATCH] thermal: intel_pch_thermal: Read large temp values correctly

From: Srinivas Pandruvada
Date: Sat Jul 29 2017 - 15:29:04 EST


On Wed, 2017-07-19 at 17:47 -0700, Ed Swierk wrote:
> On all supported platforms, the TS Reading (TSR) field in the
> Temperature (TEMP) register is 9 bits wide. Values above 0x100 (78
> degrees C) are plausible, so don't mask out the topmost bit. And the
> register itself is 16 bits wide, so use readw() rather than readl().
>
> Signed-off-by: Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>

> ---
> Âdrivers/thermal/intel_pch_thermal.c | 6 +++---
> Â1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/thermal/intel_pch_thermal.c
> b/drivers/thermal/intel_pch_thermal.c
> index 9889c90..318fc1b 100644
> --- a/drivers/thermal/intel_pch_thermal.c
> +++ b/drivers/thermal/intel_pch_thermal.c
> @@ -49,7 +49,7 @@
> Â#define WPT_TSGPEN 0x84 /* General Purpose Event
> Enables */
> Â
> Â/*ÂÂWildcat Point-LPÂÂPCH Thermal Register bit definitions */
> -#define WPT_TEMP_TSR 0x00ff /* Temp TS Reading */
> +#define WPT_TEMP_TSR 0x01ff /* Temp TS Reading */
> Â#define WPT_TSC_CPDE 0x01 /* Catastrophic Power-Down
> Enable */
> Â#define WPT_TSS_TSDSS 0x10 /* Thermal Sensor Dynamic
> Shutdown Status */
> Â#define WPT_TSS_GPES 0x08 /* GPE status */
> @@ -174,9 +174,9 @@ static int pch_wpt_init(struct pch_thermal_device
> *ptd, int *nr_trips)
> Â
> Âstatic int pch_wpt_get_temp(struct pch_thermal_device *ptd, int
> *temp)
> Â{
> - u8 wpt_temp;
> + u16 wpt_temp;
> Â
> - wpt_temp = WPT_TEMP_TSR & readl(ptd->hw_base + WPT_TEMP);
> + wpt_temp = WPT_TEMP_TSR & readw(ptd->hw_base + WPT_TEMP);
> Â
> Â /* Resolution of 1/2 degree C and an offset of -50C */
> Â *temp = (wpt_temp * 1000 / 2 - 50000);