[U-Boot] [PATCH] thermal: imx_thermal: fix busywait if IMX6 temp <0C

[U-Boot] [PATCH] thermal: imx_thermal: fix busywait if IMX6 temp <0C

[Tim Harvey]

The temperature calculation must be typecasted to keep the compiler
from sign extending a negative value prior to division.

This fixes an issue where if the CPU temperature is <0C it will get stuck
in the busywait loop until the CPU heats up to 0C.

Cc: Ye Li <b37916@freescale.com>
Cc: Jason Liu <r64343@freescale.com>
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
---
 drivers/thermal/imx_thermal.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index 0d893c9..6d1ac97 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -115,7 +115,7 @@ static int read_cpu_temperature(struct udevice *dev)
 	writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
 
 	/* milli_Tmeas = c2 - Nmeas * c1 */
-	temperature = (c2 - n_meas * c1)/1000;
+	temperature = (long)(c2 - n_meas * c1)/1000;
 
 	/* power down anatop thermal sensor */
 	writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_set);
-- 
1.9.1

[U-Boot] [PATCH] thermal: imx_thermal: fix busywait if IMX6 temp <0C

[Stefano Babic]

Hi Tim,

On 09/07/2015 00:49, Tim Harvey wrote:
> The temperature calculation must be typecasted to keep the compiler
> from sign extending a negative value prior to division.
> 
> This fixes an issue where if the CPU temperature is <0C it will get stuck
> in the busywait loop until the CPU heats up to 0C.
> 
> Cc: Ye Li <b37916@freescale.com>
> Cc: Jason Liu <r64343@freescale.com>
> Signed-off-by: Tim Harvey <tharvey@gateworks.com>
> ---
>  drivers/thermal/imx_thermal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
> index 0d893c9..6d1ac97 100644
> --- a/drivers/thermal/imx_thermal.c
> +++ b/drivers/thermal/imx_thermal.c
> @@ -115,7 +115,7 @@ static int read_cpu_temperature(struct udevice *dev)
>  	writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
>  
>  	/* milli_Tmeas = c2 - Nmeas * c1 */
> -	temperature = (c2 - n_meas * c1)/1000;
> +	temperature = (long)(c2 - n_meas * c1)/1000;
>  
>  	/* power down anatop thermal sensor */
>  	writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_set);
> 

Applied to u-boot-imx, thanks !

Best regards,
Stefano Babic


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