diff options
| author | Mike Frysinger <vapier@gentoo.org> | 2010-02-15 19:32:25 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-03-15 08:49:32 -0700 |
| commit | bec3dfd4c9e939eea52a72d20d4493233dde41eb (patch) | |
| tree | 9ff5ca86cb04c8708552de75effd3da22d8a9d89 /drivers/watchdog/bfin_wdt.c | |
| parent | 98bde14156f5e705cc0e8b18e3062656fa131bb5 (diff) | |
bfin: fix max timeout calculation
commit 3dae93ec3ee1fceec69f40ef9b97892ce62ba7a5 upstream.
Relying on overflow/wrap around isn't exact because if you wrap far
enough, you get back to "valid" values.
Reported-by: Thorsten Pohlmann <pohlmann@tetronik.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/watchdog/bfin_wdt.c')
| -rw-r--r-- | drivers/watchdog/bfin_wdt.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/drivers/watchdog/bfin_wdt.c b/drivers/watchdog/bfin_wdt.c index c7b3f9df2317..2159e668751c 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 <alan@lxorguk.ukuu.org.uk> * @@ -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; } |