[PATCH v7 0/3] Some impovements about acpi hardware watchdog

[PATCH v7 0/3] Some impovements about acpi hardware watchdog

[Liu Xinpeng]

Changelog:
v1->v2 Update the commit messages
v2->v3 - Add the context about why using watchdog_timeout_invalid.
       - Using SET_NOIRQ_SYSTEM_SLEEP_PM_OPS reduces redundant code for
       iTCO watchdog.
v3->v4 - For patch 1, update commit message, rename WDAT_TIMEOUT_MIN
       to WDAT_MIN_TIMEOUT, keeps consistent with WDAT_DEFAULT_TIMEOUT.
       - For patch 4, iTCO_wdt_suspend_noirq and iTCO_wdt_resume_noirq
       are possible unused, so keep "ifdef CONFIG_PM_SLEEP ... #endif".
v4->v5 split iTCO_wdt's commit fro this patchset.
v5->v6 For patch 1, drop "Context: " and to change "existed" in the 
subject to "existing".
v6->v7 Rename "watchdog: wdat_wdg" in subject to "watchdog: wdat_wdt"

Liu Xinpeng (3):
  watchdog: wdat_wdg: Using the existing function to check parameter
    timeout
  watchdog: wdat_wdg: Stop watchdog when rebooting the system
  watchdog: wdat_wdg: Stop watchdog when uninstalling module

 drivers/watchdog/wdat_wdt.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

-- 
2.23.0

[PATCH v7 1/3] watchdog: wdat_wdt: Using the existing function to check parameter timeout

[Liu Xinpeng]

If max_hw_heartbeat_ms is provided, the configured maximum timeout is not
limited by it. The limit check in this driver therefore doesn't make much
sense. Similar, the watchdog core ensures that minimum timeout limits are
met if min_hw_heartbeat_ms is set. Using watchdog_timeout_invalid() makes
more sense because it takes this into account.

Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
---
 drivers/watchdog/wdat_wdt.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c
index 195c8c004b69..9db01d165310 100644
--- a/drivers/watchdog/wdat_wdt.c
+++ b/drivers/watchdog/wdat_wdt.c
@@ -55,6 +55,7 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
 		 __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
 
 #define WDAT_DEFAULT_TIMEOUT	30
+#define WDAT_MIN_TIMEOUT     1
 
 static int timeout = WDAT_DEFAULT_TIMEOUT;
 module_param(timeout, int, 0);
@@ -344,6 +345,7 @@ static int wdat_wdt_probe(struct platform_device *pdev)
 	wdat->period = tbl->timer_period;
 	wdat->wdd.min_hw_heartbeat_ms = wdat->period * tbl->min_count;
 	wdat->wdd.max_hw_heartbeat_ms = wdat->period * tbl->max_count;
+	wdat->wdd.min_timeout = WDAT_MIN_TIMEOUT;
 	wdat->stopped_in_sleep = tbl->flags & ACPI_WDAT_STOPPED;
 	wdat->wdd.info = &wdat_wdt_info;
 	wdat->wdd.ops = &wdat_wdt_ops;
@@ -450,8 +452,7 @@ static int wdat_wdt_probe(struct platform_device *pdev)
 	 * watchdog properly after it has opened the device. In some cases
 	 * the BIOS default is too short and causes immediate reboot.
 	 */
-	if (timeout * 1000 < wdat->wdd.min_hw_heartbeat_ms ||
-	    timeout * 1000 > wdat->wdd.max_hw_heartbeat_ms) {
+	if (watchdog_timeout_invalid(&wdat->wdd, timeout)) {
 		dev_warn(dev, "Invalid timeout %d given, using %d\n",
 			 timeout, WDAT_DEFAULT_TIMEOUT);
 		timeout = WDAT_DEFAULT_TIMEOUT;
-- 
2.23.0

[PATCH v7 2/3] watchdog: wdat_wdt: Stop watchdog when rebooting the system

[Liu Xinpeng]

Executing reboot command several times on the machine "Dell
PowerEdge R740", UEFI security detection stopped machine
with the following prompt:

UEFI0082: The system was reset due to a timeout from the watchdog
timer. Check the System Event Log (SEL) or crash dumps from
Operating Sysstem to identify the source that triggered the
watchdog timer reset. Update the firmware or driver for the
identified device.

iDRAC has warning event: "The watchdog timer reset the system".

This patch fixes this issue by adding the reboot notifier.

Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
---
 drivers/watchdog/wdat_wdt.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c
index 9db01d165310..0ef2b918364a 100644
--- a/drivers/watchdog/wdat_wdt.c
+++ b/drivers/watchdog/wdat_wdt.c
@@ -463,6 +463,7 @@ static int wdat_wdt_probe(struct platform_device *pdev)
 		return ret;
 
 	watchdog_set_nowayout(&wdat->wdd, nowayout);
+	watchdog_stop_on_reboot(&wdat->wdd);
 	return devm_watchdog_register_device(dev, &wdat->wdd);
 }
 
-- 
2.23.0

[PATCH v7 3/3] watchdog: wdat_wdt: Stop watchdog when uninstalling module

[Liu Xinpeng]

Test shows that wachdog still reboots machine after the module
is removed. Use watchdog_stop_on_unregister to stop the watchdog
on removing.

Signed-off-by: Liu Xinpeng <liuxp11@chinatelecom.cn>
---
 drivers/watchdog/wdat_wdt.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/watchdog/wdat_wdt.c b/drivers/watchdog/wdat_wdt.c
index 0ef2b918364a..6732d7fc4f94 100644
--- a/drivers/watchdog/wdat_wdt.c
+++ b/drivers/watchdog/wdat_wdt.c
@@ -464,6 +464,7 @@ static int wdat_wdt_probe(struct platform_device *pdev)
 
 	watchdog_set_nowayout(&wdat->wdd, nowayout);
 	watchdog_stop_on_reboot(&wdat->wdd);
+	watchdog_stop_on_unregister(&wdat->wdd);
 	return devm_watchdog_register_device(dev, &wdat->wdd);
 }
 
-- 
2.23.0