From: Huibin Hong Date: Thu, 27 Jul 2017 12:27:09 +0000 (+0800) Subject: watchdog: dw_wdt: fix overflow issue in dw_wdt_top_in_seconds X-Git-Tag: release-20171130_firefly~4^2~84 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=e8b7cbd64ac23c3f780a52bccd24d0bc5b91f76f;p=firefly-linux-kernel-4.4.55.git 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 --- 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)