diff options
| author | Dien Pham <dien.pham.ry@renesas.com> | 2020-06-25 20:38:19 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-09 09:37:53 +0200 |
| commit | 31ec38ec9cd523e9448163962cdaae2c7f2662b5 (patch) | |
| tree | fb0ce96ab9bc4c9201501072c9a0663279dec9ff /drivers/thermal | |
| parent | a65bde0010088abdb431758d241fddb795731f9b (diff) | |
thermal/drivers/rcar_gen3: Fix undefined temperature if negative
[ Upstream commit 5f8f06425a0dcdad7bedbb77e67f5c65ab4dacfc ]
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
Signed-off-by: Sasha Levin <sashal@kernel.org>
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 755d2b5bd2c2..1ab2ffff4e7c 100644 --- a/drivers/thermal/rcar_gen3_thermal.c +++ b/drivers/thermal/rcar_gen3_thermal.c @@ -169,7 +169,7 @@ 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; |