• Petr Pavlu's avatar
    ipmi/watchdog: Stop watchdog timer when the current action is 'none' · 2253042d
    Petr Pavlu authored
    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: default avatarPetr Pavlu <petr.pavlu@suse.com>
    Message-Id: <10a41bdc-9c99-089c-8d89-fa98ce5ea080@suse.com>
    Cc: stable@vger.kernel.org
    Signed-off-by: default avatarCorey Minyard <cminyard@mvista.com>
    2253042d
ipmi_watchdog.c 32 KB