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| author | Dien Pham <dien.pham.ry@renesas.com> | 2020-06-25 14:38:19 +0300 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2020-06-29 13:15:34 +0300 |
| commit | 5f8f06425a0dcdad7bedbb77e67f5c65ab4dacfc (patch) | |
| tree | 97e6f855be0429972cdb6fb4b994080717a6051e /drivers/thermal | |
| parent | 371a3bc79c11b707d7a1b7a2c938dc3cc042fffb (diff) | |
| download | linux-5f8f06425a0dcdad7bedbb77e67f5c65ab4dacfc.tar.xz | |
thermal/drivers/rcar_gen3: Fix undefined temperature if negative
As description for DIV_ROUND_CLOSEST in file include/linux/kernel.h.
"Result is undefined for negative divisors if the dividend variable
type is unsigned and for negative dividends if the divisor variable
type is unsigned."
In current code, the FIXPT_DIV uses DIV_ROUND_CLOSEST but has not
checked sign of divisor before using. It makes undefined temperature
value in case the value is negative.
This patch fixes to satisfy DIV_ROUND_CLOSEST description
and fix bug too. Note that the variable name "reg" is not good
because it should be the same type as rcar_gen3_thermal_read().
However, it's better to rename the "reg" in a further patch as
cleanup.
Signed-off-by: Van Do <van.do.xw@renesas.com>
Signed-off-by: Dien Pham <dien.pham.ry@renesas.com>
[shimoda: minor fixes, add Fixes tag]
Fixes: 564e73d283af ("thermal: rcar_gen3_thermal: Add R-Car Gen3 thermal driver")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Niklas Soderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Niklas Soderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1593085099-2057-1-git-send-email-yoshihiro.shimoda.uh@renesas.com
Diffstat (limited to 'drivers/thermal')
| -rw-r--r-- | drivers/thermal/rcar_gen3_thermal.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c index 58fe7c1ef00b..c48c5e9b8f20 100644 --- a/drivers/thermal/rcar_gen3_thermal.c +++ b/drivers/thermal/rcar_gen3_thermal.c @@ -167,7 +167,7 @@ static int rcar_gen3_thermal_get_temp(void *devdata, int *temp) { struct rcar_gen3_thermal_tsc *tsc = devdata; int mcelsius, val; - u32 reg; + int reg; /* Read register and convert to mili Celsius */ reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK; |