Revert "watchdog: iTCO_wdt: Account for rebooting on second timeout"

This reverts commit cb011044e34c ("watchdog: iTCO_wdt: Account for
rebooting on second timeout") and commit aec42642d91f ("watchdog: iTCO_wdt:
Fix detection of SMI-off case") since those patches cause a regression
on certain boards (https://bugzilla.kernel.org/show_bug.cgi?id=213809).

While this revert may result in some boards to only reset after twice
the configured timeout value, that is still better than a watchdog reset
after half the configured value.

Fixes: cb011044e34c ("watchdog: iTCO_wdt: Account for rebooting on second timeout")
Fixes: aec42642d91f ("watchdog: iTCO_wdt: Fix detection of SMI-off case")
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Mantas Mikulėnas <grawity@gmail.com>
Reported-by: Javier S. Pedro <debbugs@javispedro.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20211008003302.1461733-1-linux@roeck-us.net
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

diff --git a/drivers/watchdog/iTCO_wdt.c b/drivers/watchdog/iTCO_wdt.c
index 643c6c2..ced2fc0 100644 (file)
--- 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 watchdog_device *wd_dev, unsigned int t)
 
        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 &&
-           (inl(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 platform_device *pdev)
                 * 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));
        }