6.1-stable review patch. If anyone has any objections, please let me know.
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From: Sangwook Shin sw617.shin@samsung.com
[ Upstream commit df3c6e0b6d83450563d6266e1dacc7eaf25511f4 ]
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 Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/watchdog/s3c2410_wdt.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c index d3fc8ed886fff..3853be982cd3c 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 @@ -303,9 +304,14 @@ 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 inline struct s3c2410_wdt *freq_to_wdt(struct notifier_block *nb)