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authorDien Pham <dien.pham.ry@renesas.com>2020-06-25 20:38:19 +0900
committerPaul Gortmaker <paul.gortmaker@windriver.com>2020-07-24 16:24:27 -0400
commit301b86e3e565aff0f63df6886edf9bad3190e200 (patch)
tree4d488702d9afd82bc1e17ab7756f82beeec61054
parent92679ebf5e692342e46c4b9ea104953301e21efe (diff)
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thermal/drivers/rcar_gen3: Fix undefined temperature if negative
commit 5f8f06425a0dcdad7bedbb77e67f5c65ab4dacfc upstream. 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: Paul Gortmaker <paul.gortmaker@windriver.com>
-rw-r--r--drivers/thermal/rcar_gen3_thermal.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/thermal/rcar_gen3_thermal.c b/drivers/thermal/rcar_gen3_thermal.c
index a56463308694..7a890bde4cff 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;