linux-kernel - [PATCH 5.4 17/23] Revert "watchdog: iTCO_wdt: Account for rebooting on second timeout"

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Date:   Fri,  6 Aug 2021 10:16:49 +0200
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Jean Delvare <jdelvare@...e.de>,
        Jan Kiszka <jan.kiszka@...mens.com>,
        Guenter Roeck <linux@...ck-us.net>,
        Wim Van Sebroeck <wim@...ux-watchdog.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.4 17/23] Revert "watchdog: iTCO_wdt: Account for rebooting on second timeout"

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

This reverts commit f58ab0b02ee7b095e0cae4ba706caa86fff5557b 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@...e.de>
Cc: Jan Kiszka <jan.kiszka@...mens.com>
Cc: Guenter Roeck <linux@...ck-us.net>
Cc: Guenter Roeck <linux@...ck-us.net>
Cc: Wim Van Sebroeck <wim@...ux-watchdog.org>
Cc: Sasha Levin <sashal@...nel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.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
@@ -72,8 +72,6 @@
 #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*/
@@ -346,12 +344,8 @@ 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: */
@@ -516,7 +510,7 @@ 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));
 	}