diff options
| author | Sangwook Shin <sw617.shin@samsung.com> | 2025-08-18 11:18:23 +0900 |
|---|---|---|
| committer | Wim Van Sebroeck <wim@linux-watchdog.org> | 2025-09-12 18:06:32 +0200 |
| commit | df3c6e0b6d83450563d6266e1dacc7eaf25511f4 (patch) | |
| tree | 92587791ff374eb5dce3099f427654b512f3be55 | |
| parent | e76bb4ee92dc6b4f21eb13d79b5c190b2e5a97e5 (diff) | |
watchdog: s3c2410_wdt: Fix max_timeout being calculated larger
Fix the issue of max_timeout being calculated larger than actual value.
The calculation result of freq / (S3C2410_WTCON_PRESCALE_MAX + 1) /
S3C2410_WTCON_MAXDIV is smaller than the actual value because the remainder
is discarded during the calculation process. This leads to a larger
calculated value for max_timeout compared to the actual settable value.
To resolve this issue, the order of calculations in the computation process
has been adjusted.
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Sangwook Shin <sw617.shin@samsung.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
| -rw-r--r-- | drivers/watchdog/s3c2410_wdt.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c index 95f7207e390a..1e8cf0299713 100644 --- a/drivers/watchdog/s3c2410_wdt.c +++ b/drivers/watchdog/s3c2410_wdt.c @@ -27,6 +27,7 @@ #include <linux/mfd/syscon.h> #include <linux/regmap.h> #include <linux/delay.h> +#include <linux/math64.h> #define S3C2410_WTCON 0x00 #define S3C2410_WTDAT 0x04 @@ -410,9 +411,14 @@ static inline unsigned long s3c2410wdt_get_freq(struct s3c2410_wdt *wdt) static inline unsigned int s3c2410wdt_max_timeout(struct s3c2410_wdt *wdt) { const unsigned long freq = s3c2410wdt_get_freq(wdt); + const u64 n_max = (u64)(S3C2410_WTCON_PRESCALE_MAX + 1) * + S3C2410_WTCON_MAXDIV * S3C2410_WTCNT_MAXCNT; + u64 t_max = div64_ul(n_max, freq); - return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1) - / S3C2410_WTCON_MAXDIV); + if (t_max > UINT_MAX) + t_max = UINT_MAX; + + return t_max; } static int s3c2410wdt_disable_wdt_reset(struct s3c2410_wdt *wdt, bool mask) |