[PATCH 5.13 34/35] Revert "watchdog: iTCO_wdt: Account for rebooting on second timeout"

Greg Kroah-Hartman
2021-08-06T08:24:38Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 5e65819a006ec8a8df2f8639dc26ef0cfaa95ae7 which is
commit cb011044e34c293e139570ce5c01aed66a34345c upstream.

It is reported to cause problems with systems and probably should not
have been backported in the first place :(

Link: https://lore.kernel.org/r/20210803165108.4154cd52@endymion
Reported-by: Jean Delvare <jdelvare@suse.de>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/watchdog/iTCO_wdt.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)

--- a/drivers/watchdog/iTCO_wdt.c
+++ b/drivers/watchdog/iTCO_wdt.c
@@ -71,8 +71,6 @@
#define TCOBASE(p) ((p)->tco_res->start)
/* SMI Control and Enable Register */
#define SMI_EN(p) ((p)->smi_res->start)
-#define TCO_EN (1 << 13)
-#define GBL_SMI_EN (1 << 0)

#define TCO_RLD(p) (TCOBASE(p) + 0x00) /* TCO Timer Reload/Curr. Value */
#define TCOv1_TMR(p) (TCOBASE(p) + 0x01) /* TCOv1 Timer Initial Value*/
@@ -357,12 +355,8 @@ static int iTCO_wdt_set_timeout(struct w

tmrval = seconds_to_ticks(p, t);

- /*
- * If TCO SMIs are off, the timer counts down twice before rebooting.
- * Otherwise, the BIOS generally reboots when the SMI triggers.
- */
- if (p->smi_res &&
- (SMI_EN(p) & (TCO_EN | GBL_SMI_EN)) != (TCO_EN | GBL_SMI_EN))
+ /* For TCO v1 the timer counts down twice before rebooting */
+ if (p->iTCO_version == 1)
tmrval /= 2;

/* from the specs: */
@@ -527,7 +521,7 @@ static int iTCO_wdt_probe(struct platfor
* Disables TCO logic generating an SMI#
*/
val32 = inl(SMI_EN(p));
- val32 &= ~TCO_EN; /* Turn off SMI clearing watchdog */
+ val32 &= 0xffffdfff; /* Turn off SMI clearing watchdog */
outl(val32, SMI_EN(p));
}