From 4f39d575844148fbf3081571a1f3b4ae04150958 Mon Sep 17 00:00:00 2001 From: Ahmad Fatoum Date: Thu, 11 Jun 2020 21:17:45 +0200 Subject: [PATCH] watchdog: f71808e_wdt: clear watchdog timeout occurred flag The flag indicating a watchdog timeout having occurred normally persists till Power-On Reset of the Fintek Super I/O chip. The user can clear it by writing a `1' to the bit. The driver doesn't offer a restart method, so regular system reboot might not reset the Super I/O and if the watchdog isn't enabled, we won't touch the register containing the bit on the next boot. In this case all subsequent regular reboots will be wrongly flagged by the driver as being caused by the watchdog. Fix this by having the flag cleared after read. This is also done by other drivers like those for the i6300esb and mpc8xxx_wdt. Fixes: b97cb21a4634 ("watchdog: f71808e_wdt: Fix WDTMOUT_STS register read") Cc: stable@vger.kernel.org Signed-off-by: Ahmad Fatoum Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20200611191750.28096-5-a.fatoum@pengutronix.de Signed-off-by: Guenter Roeck Signed-off-by: Wim Van Sebroeck --- drivers/watchdog/f71808e_wdt.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c index 8e5584c54423..26bf366aebc2 100644 --- a/drivers/watchdog/f71808e_wdt.c +++ b/drivers/watchdog/f71808e_wdt.c @@ -706,6 +706,13 @@ static int __init watchdog_init(int sioaddr) wdt_conf = superio_inb(sioaddr, F71808FG_REG_WDT_CONF); watchdog.caused_reboot = wdt_conf & BIT(F71808FG_FLAG_WDTMOUT_STS); + /* + * We don't want WDTMOUT_STS to stick around till regular reboot. + * Write 1 to the bit to clear it to zero. + */ + superio_outb(sioaddr, F71808FG_REG_WDT_CONF, + wdt_conf | BIT(F71808FG_FLAG_WDTMOUT_STS)); + superio_exit(sioaddr); err = watchdog_set_timeout(timeout);