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authorAhmad Fatoum <a.fatoum@pengutronix.de>2020-06-11 22:17:45 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-08-21 12:05:33 +0300
commite1462b5e6a052221d06d064d28a2f16c4e1782f6 (patch)
tree544132de87d050fe11a875d28a253155d098e12a /drivers/watchdog
parent49d0707efdad02d15c627ba19629c81a367748b1 (diff)
downloadlinux-e1462b5e6a052221d06d064d28a2f16c4e1782f6.tar.xz
watchdog: f71808e_wdt: clear watchdog timeout occurred flag
commit 4f39d575844148fbf3081571a1f3b4ae04150958 upstream. 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 <a.fatoum@pengutronix.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20200611191750.28096-5-a.fatoum@pengutronix.de Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/watchdog')
-rw-r--r--drivers/watchdog/f71808e_wdt.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/watchdog/f71808e_wdt.c b/drivers/watchdog/f71808e_wdt.c
index 608eeba3270b..5d0ea419070d 100644
--- a/drivers/watchdog/f71808e_wdt.c
+++ b/drivers/watchdog/f71808e_wdt.c
@@ -704,6 +704,13 @@ 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);