Re: [PATCH v4 06/10] thermal: rockchip: consistently use int for temperatures

From: Brian Norris
Date: Wed Dec 02 2015 - 13:46:23 EST


Hi Caesar,

On Mon, Nov 09, 2015 at 12:48:58PM +0800, Caesar Wang wrote:
> As Temperature is currently represented as int not long in the thermal
> framework since use int intead of unsigned long/long to represent
> temperature to avoid bogus overheat detection when negative temperature
> reported.
>
> Signed-off-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>
>
> ---
>
> Changes in v4:
> - fix the warning from the print message.
>
> Changes in v3:
> - As the Patch v2 comments, Add a new patch to fix it.
>
> Changes in v2: None
> Changes in v1: None
>
> drivers/thermal/rockchip_thermal.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/thermal/rockchip_thermal.c b/drivers/thermal/rockchip_thermal.c
> index 7c5b784..73d47f8 100644
> --- a/drivers/thermal/rockchip_thermal.c
> +++ b/drivers/thermal/rockchip_thermal.c
> @@ -88,7 +88,7 @@ struct rockchip_tsadc_chip {
> int chn_num;
>
> /* The hardware-controlled tshut property */
> - long tshut_temp;
> + int tshut_temp;
> enum tshut_mode tshut_mode;
> enum tshut_polarity tshut_polarity;
>

...

> @@ -126,7 +126,7 @@ struct rockchip_thermal_data {
>
> void __iomem *regs;
>
> - long tshut_temp;
> + int tshut_temp;

FYI, this change is triggering a new warning in Coverity, below:

> enum tshut_mode tshut_mode;
> enum tshut_polarity tshut_polarity;
> };

...

> @@ -477,7 +477,7 @@ static int rockchip_configure_from_dt(struct device *dev,
> }
>
> if (thermal->tshut_temp > INT_MAX) {

CID 1341498: Integer handling issues (CONSTANT_EXPRESSION_RESULT)
"thermal->tshut_temp > 2147483647 /* (int)(~0U >> 1) */" is always false regardless of the values of its operands. This occurs as the logical operand of if.

I don't think this condition is even useful any more, so maybe we should
just kill the 'if' block.

> - dev_err(dev, "Invalid tshut temperature specified: %ld\n",
> + dev_err(dev, "Invalid tshut temperature specified: %d\n",
> thermal->tshut_temp);
> return -ERANGE;
> }

Brian
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