RE: [PATCH v3 RESEND 2/5] watchdog: s3c2410_wdt: Fix max_timeout being calculated larger
From: "Alim Akhtar" <alim.akhtar@samsung.com>
Date: 2025-07-24 05:54:01
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linux-samsung-soc, linux-watchdog, lkml
-----Original Message----- From: Sangwook Shin <redacted> Sent: Monday, July 14, 2025 11:25 AM To: krzk@kernel.org; alim.akhtar@samsung.com; wim@linux-watchdog.org; linux@roeck-us.net Cc: linux-arm-kernel@lists.infradead.org; linux-samsung- soc@vger.kernel.org; linux-watchdog@vger.kernel.org; linux- kernel@vger.kernel.org; Sangwook Shin [off-list ref] Subject: [PATCH v3 RESEND 2/5] 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. A ceiling operation is applied in the calculation process to resolve this. Signed-off-by: Sangwook Shin <redacted> ---
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
quoted hunk ↗ jump to hunk
drivers/watchdog/s3c2410_wdt.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)diff --git a/drivers/watchdog/s3c2410_wdt.cb/drivers/watchdog/s3c2410_wdt.c index 95f7207e390a..31f7e1ec779e 100644--- a/drivers/watchdog/s3c2410_wdt.c +++ b/drivers/watchdog/s3c2410_wdt.c@@ -411,8 +411,8 @@ static inline unsigned ints3c2410wdt_max_timeout(struct s3c2410_wdt *wdt) { const unsigned long freq = s3c2410wdt_get_freq(wdt); - return S3C2410_WTCNT_MAXCNT / (freq / (S3C2410_WTCON_PRESCALE_MAX + 1) - / S3C2410_WTCON_MAXDIV); + return S3C2410_WTCNT_MAXCNT / DIV_ROUND_UP(freq, + (S3C2410_WTCON_PRESCALE_MAX + 1) * S3C2410_WTCON_MAXDIV); } static int s3c2410wdt_disable_wdt_reset(struct s3c2410_wdt *wdt, bool mask) -- 2.25.1