[PATCH] watchdog: meson_gxbb_wdt: fix suspend/resume handling of HW_RUNNING watchdog

[Igor Velkov via B4 Relay]

From: Igor Velkov <iav@xxxxxx>

meson_gxbb_wdt_suspend() and meson_gxbb_wdt_resume() only check
watchdog_active(). Since commit 6adbfbab0f03 ("watchdog: meson: keep
running if already active"), probe keeps a watchdog left running by the
bootloader and sets WDOG_HW_RUNNING. If userspace never opens the
device, WDOG_ACTIVE stays clear and the timer is not stopped for system
suspend.

On an ODROID-HC4 (S905X3) whose U-Boot starts the watchdog, with no
userspace owner, the board does not wake from deep suspend
(rtcwake -m mem -s 60) in 2 of 2 attempts and needs a power cycle.

Stop the timer on suspend and restart it on resume also when it is only
running in hardware, as sp805_wdt does. With this change the board
wakes from deep suspend in 4 of 4 attempts, and the kernel pings the
watchdog again after resume.

Fixes: 6adbfbab0f03 ("watchdog: meson: keep running if already active")
Assisted-by: LLM
Signed-off-by: Igor Velkov <iav@xxxxxx>
---
The same change as commit 1c81d4a5cda2 ("watchdog: sp805_wdt: fix
suspend/resume handling of HW_RUNNING watchdog") in watchdog-next.
---
 drivers/watchdog/meson_gxbb_wdt.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/watchdog/meson_gxbb_wdt.c b/drivers/watchdog/meson_gxbb_wdt.c
index fb276060e831..fa6953d106ac 100644
--- a/drivers/watchdog/meson_gxbb_wdt.c
+++ b/drivers/watchdog/meson_gxbb_wdt.c
@@ -124,7 +124,8 @@ static int __maybe_unused meson_gxbb_wdt_resume(struct device *dev)
 {
 	struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
 
-	if (watchdog_active(&data->wdt_dev))
+	if (watchdog_active(&data->wdt_dev) ||
+	    watchdog_hw_running(&data->wdt_dev))
 		meson_gxbb_wdt_start(&data->wdt_dev);
 
 	return 0;
@@ -134,7 +135,8 @@ static int __maybe_unused meson_gxbb_wdt_suspend(struct device *dev)
 {
 	struct meson_gxbb_wdt *data = dev_get_drvdata(dev);
 
-	if (watchdog_active(&data->wdt_dev))
+	if (watchdog_active(&data->wdt_dev) ||
+	    watchdog_hw_running(&data->wdt_dev))
 		meson_gxbb_wdt_stop(&data->wdt_dev);
 
 	return 0;

---
base-commit: 6276c8195e598361942082423114877265c17692
change-id: 20261020-meson-gxbb-wdt-suspend-ad77f97606a8

Best regards,
-- 
Igor Velkov <iav@xxxxxx>