| From c4c4727cbe9f221e428f9bbe89c20a5025aeea9a Mon Sep 17 00:00:00 2001 |
| From: Dien Pham <dien.pham.ry@renesas.com> |
| Date: Thu, 25 Jun 2020 20:38:19 +0900 |
| Subject: [PATCH] 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> |
| |
| 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; |
| -- |
| 2.27.0 |
| |
