Re: [PATCH v3 2/5] thermal: rockchip: fix a impossible condition caused by the warning

[Caesar Wang]

在 2015年12月04日 04:19, Dmitry Torokhov 写道:

On Thu, Dec 03, 2015 at 04:48:40PM +0800, Caesar Wang wrote:

As the Dan report the smatch check the thermal driver warning:
drivers/thermal/rockchip_thermal.c:551 rockchip_configure_from_dt()
warn: impossible condition '(thermal->tshut_temp > ((~0 >> 1))) =>
(s32min-s32max > s32max)'

Let's we remove the imposssible condition Since the Temperature is
currently represented as int not long in the thermal driver.

Fixes: commit 437df2172e8d
("thermal: rockchip: consistently use int for temperatures")

Reported-by: Dan Carpenter <dan.carpen...@oracle.com>
Signed-off-by: Caesar Wang <w...@rock-chips.com>

---

Changes in v3:
- As Brian comments on https://patchwork.kernel.org/patch/7580661/,
   let's remove the impossible condition.

Changes in v2: None
Changes in v1: None

  drivers/thermal/rockchip_thermal.c | 6 ------
  1 file changed, 6 deletions(-)

diff --git a/drivers/thermal/rockchip_thermal.c 
b/drivers/thermal/rockchip_thermal.c
index ae796ec..611de00 100644
--- a/drivers/thermal/rockchip_thermal.c
+++ b/drivers/thermal/rockchip_thermal.c
@@ -549,12 +549,6 @@ static int rockchip_configure_from_dt(struct device *dev,
                thermal->tshut_temp = shut_temp;
        }

- if (thermal->tshut_temp > INT_MAX) {

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

Well, that is not entirely correct. The value that we read from DT is
u32, but we convert it down to int. I believe you want to move the check
up so that you do:

        } else if (tshut_temp > INT_MAX) {
                dev_err(dev, "Invalid tshut temperature specified: %d\n",
                        thermal->tshut_temp);
                return -ERANGE;
        } else {
                thermal->tshut_temp = shut_temp;
        }

Okay,
that's seem the following wll be resonable since the checkcode is a warning.

if (of_property_read_u32(np, "rockchip,hw-tshut-temp", &shut_temp)) {
        dev_warn(dev,
             "Missing tshut temp property, using default %d\n",
             thermal->chip->tshut_temp);
        thermal->tshut_temp = thermal->chip->tshut_temp;
    } else {
        if (tshut_temp > INT_MAX) {
            dev_err(dev, "Invalid tshut temperature specified: %d\n",
                tshut_temp);
            return -ERANGE;
        }
        thermal->tshut_temp = shut_temp;
    }

Thanks,

Thanks.

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