From 3dae93ec3ee1fceec69f40ef9b97892ce62ba7a5 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Mon, 15 Feb 2010 19:32:25 -0500 Subject: [WATCHDOG] bfin: fix max timeout calculation Relying on overflow/wrap around isn't exact because if you wrap far enough, you get back to "valid" values. Reported-by: Thorsten Pohlmann Signed-off-by: Mike Frysinger Signed-off-by: Wim Van Sebroeck Cc: stable --- drivers/watchdog/bfin_wdt.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'drivers/watchdog') diff --git a/drivers/watchdog/bfin_wdt.c b/drivers/watchdog/bfin_wdt.c index c7b3f9df231..2159e668751 100644 --- a/drivers/watchdog/bfin_wdt.c +++ b/drivers/watchdog/bfin_wdt.c @@ -1,9 +1,8 @@ /* * Blackfin On-Chip Watchdog Driver - * Supports BF53[123]/BF53[467]/BF54[2489]/BF561 * * Originally based on softdog.c - * Copyright 2006-2007 Analog Devices Inc. + * Copyright 2006-2010 Analog Devices Inc. * Copyright 2006-2007 Michele d'Amico * Copyright 1996 Alan Cox * @@ -137,13 +136,15 @@ static int bfin_wdt_running(void) */ static int bfin_wdt_set_timeout(unsigned long t) { - u32 cnt; + u32 cnt, max_t, sclk; unsigned long flags; - stampit(); + sclk = get_sclk(); + max_t = -1 / sclk; + cnt = t * sclk; + stamp("maxtimeout=%us newtimeout=%lus (cnt=%#x)", max_t, t, cnt); - cnt = t * get_sclk(); - if (cnt < get_sclk()) { + if (t > max_t) { printk(KERN_WARNING PFX "timeout value is too large\n"); return -EINVAL; } -- cgit v1.2.3-18-g5258