From 2253042d86f57d90a621ac2513a7a7a13afcf809 Mon Sep 17 00:00:00 2001

From: Petr Pavlu <petr.pavlu@suse.com>

Date: Thu, 13 May 2021 14:26:36 +0200

Subject: [PATCH] ipmi/watchdog: Stop watchdog timer when the current action is

 'none'

Patch-mainline: Queued in subsystem maintainer repository

Git-repo: git://github.com/cminyard/linux-ipmi.git

Git-commit: 2253042d86f57d90a621ac2513a7a7a13afcf809

References: bsc#1184855

When an IPMI watchdog timer is being stopped in ipmi_close() or

ipmi_ioctl(WDIOS_DISABLECARD), the current watchdog action is updated to

WDOG_TIMEOUT_NONE and _ipmi_set_timeout(IPMI_SET_TIMEOUT_NO_HB) is called

to install this action. The latter function ends up invoking

__ipmi_set_timeout() which makes the actual 'Set Watchdog Timer' IPMI

request.

For IPMI 1.0, this operation results in fully stopping the watchdog timer.

For IPMI >= 1.5, function __ipmi_set_timeout() always specifies the "don't

stop" flag in the prepared 'Set Watchdog Timer' IPMI request. This causes

that the watchdog timer has its action correctly updated to 'none' but the

timer continues to run. A problem is that IPMI firmware can then still log

an expiration event when the configured timeout is reached, which is

unexpected because the watchdog timer was requested to be stopped.

The patch fixes this problem by not setting the "don't stop" flag in

__ipmi_set_timeout() when the current action is WDOG_TIMEOUT_NONE which

results in stopping the watchdog timer. This makes the behaviour for

IPMI >= 1.5 consistent with IPMI 1.0. It also matches the logic in

__ipmi_heartbeat() which does not allow to reset the watchdog if the

current action is WDOG_TIMEOUT_NONE as that would start the timer.

Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>

Message-Id: <10a41bdc-9c99-089c-8d89-fa98ce5ea080@suse.com>

Cc: stable@vger.kernel.org

Signed-off-by: Corey Minyard <cminyard@mvista.com>

---

 drivers/char/ipmi/ipmi_watchdog.c | 22 ++++++++++++----------

 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/char/ipmi/ipmi_watchdog.c b/drivers/char/ipmi/ipmi_watchdog.c

index 32c334e34d55..e4ff3b50de7f 100644

--- a/drivers/char/ipmi/ipmi_watchdog.c

+++ b/drivers/char/ipmi/ipmi_watchdog.c

@@ -371,16 +371,18 @@ static int __ipmi_set_timeout(struct ipmi_smi_msg  *smi_msg,

 	data[0] = 0;

 	WDOG_SET_TIMER_USE(data[0], WDOG_TIMER_USE_SMS_OS);

-	if ((ipmi_version_major > 1)

-	    || ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {

-		/* This is an IPMI 1.5-only feature. */

-		data[0] |= WDOG_DONT_STOP_ON_SET;

-	} else if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {

-		/*

-		 * In ipmi 1.0, setting the timer stops the watchdog, we

-		 * need to start it back up again.

-		 */

-		hbnow = 1;

+	if (ipmi_watchdog_state != WDOG_TIMEOUT_NONE) {

+		if ((ipmi_version_major > 1) ||

+		    ((ipmi_version_major == 1) && (ipmi_version_minor >= 5))) {

+			/* This is an IPMI 1.5-only feature. */

+			data[0] |= WDOG_DONT_STOP_ON_SET;

+		} else {

+			/*

+			 * In ipmi 1.0, setting the timer stops the watchdog, we

+			 * need to start it back up again.

+			 */

+			hbnow = 1;

+		}

 	}

 	data[1] = 0;

-- 

2.26.2