From e8b7cbd64ac23c3f780a52bccd24d0bc5b91f76f Mon Sep 17 00:00:00 2001 From: Huibin Hong Date: Thu, 27 Jul 2017 20:27:09 +0800 Subject: [PATCH] watchdog: dw_wdt: fix overflow issue in dw_wdt_top_in_seconds If top is 15, (1 << (16 + top)) may be negative. Change-Id: I76e4a603a54f093e64a4b266008570e3afcdb35a Signed-off-by: Huibin Hong --- drivers/watchdog/dw_wdt.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index 6ea0634345e9..059c9746f5f7 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -81,7 +81,9 @@ static inline int dw_wdt_top_in_seconds(unsigned top) * There are 16 possible timeout values in 0..15 where the number of * cycles is 2 ^ (16 + i) and the watchdog counts down. */ - return (1 << (16 + top)) / clk_get_rate(dw_wdt.clk); + unsigned int cycles = 1 << (16 + top); + + return cycles / clk_get_rate(dw_wdt.clk); } static int dw_wdt_get_top(void) -- 2.34.1