Re: [PATCH -next] watchdog: sbsa: Test WDOG_HW_RUNNING bit in suspend and resume

From: Guenter Roeck
Date: Sat Mar 04 2023 - 09:55:12 EST


On 3/1/23 03:37, Wang Wensheng wrote:
If the sbsa_gwdt is enabled by BIOS, the kernel set WDOG_HW_RUNNING bit
and keep it alive before anyone else would open it. When system suspend,
the sbsa_gwdt would not be disabled because WDOG_ACTIVE is not set. Then
the sbsa_gwdt would reach timeout since no one touch it during system
suspend.

To solve this, just test WDOG_HW_RUNNING bit in suspend and disable the
sbsa_gwdt if the bit is set, then reopen it accordingly in resume
process.

Signed-off-by: Wang Wensheng <wangwensheng4@xxxxxxxxxx>
---
drivers/watchdog/sbsa_gwdt.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/sbsa_gwdt.c b/drivers/watchdog/sbsa_gwdt.c
index 9791c74aebd4..60875a710e43 100644
--- a/drivers/watchdog/sbsa_gwdt.c
+++ b/drivers/watchdog/sbsa_gwdt.c
@@ -360,7 +360,7 @@ static int __maybe_unused sbsa_gwdt_suspend(struct device *dev)
{
struct sbsa_gwdt *gwdt = dev_get_drvdata(dev);
- if (watchdog_active(&gwdt->wdd))
+ if (watchdog_hw_running(&gwdt->wdd))
sbsa_gwdt_stop(&gwdt->wdd);

That will not stop the watchdog if it is currently open (active)
and if it wasn't running when the module was loaded.

Guenter

return 0;
@@ -371,7 +371,7 @@ static int __maybe_unused sbsa_gwdt_resume(struct device *dev)
{
struct sbsa_gwdt *gwdt = dev_get_drvdata(dev);
- if (watchdog_active(&gwdt->wdd))
+ if (watchdog_hw_running(&gwdt->wdd))
sbsa_gwdt_start(&gwdt->wdd);
return 0;