From: Petr Pavlu petr.pavlu@suse.com
commit 2253042d86f57d90a621ac2513a7a7a13afcf809 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/char/ipmi/ipmi_watchdog.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-)
--- a/drivers/char/ipmi/ipmi_watchdog.c +++ b/drivers/char/ipmi/ipmi_watchdog.c @@ -394,16 +394,18 @@ static int i_ipmi_set_timeout(struct ipm 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;