[PATCH] watchdog: shwdt: register device only after full driver init

[Cong Nguyen <congnt264@gmail.com>]

sh_wdt_probe() calls watchdog_register_device() -- exposing
/dev/watchdogN -- before timer_setup() and pm_runtime_enable() run. A
start command landing in that window calls mod_timer() on an
uninitialized timer (NULL ->function) and resumes via
pm_runtime_get_sync() before PM is enabled.

Move timer_setup() and pm_runtime_enable() before the register call,
matching the order already used by rzg2l_wdt.c/rzv2h_wdt.c. Add
pm_runtime_disable() on the now-possible post-enable register-failure
path.

Fixes: 8f5585ec3d17 ("watchdog: shwdt: driver model conversion.")
Assisted-by: Claude:claude-opus-4
Signed-off-by: Cong Nguyen <congnt264@gmail.com>
---
 drivers/watchdog/shwdt.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/watchdog/shwdt.c b/drivers/watchdog/shwdt.c
index 719f100aae60..c22b8e760476 100644
--- a/drivers/watchdog/shwdt.c
+++ b/drivers/watchdog/shwdt.c
@@ -263,19 +263,20 @@ static int sh_wdt_probe(struct platform_device *pdev)
 	dev_info(&pdev->dev, "configured with heartbeat=%d sec (nowayout=%d)\n",
 		 sh_wdt_dev.timeout, nowayout);
 
+	timer_setup(&wdt->timer, sh_wdt_ping, 0);
+	wdt->timer.expires	= next_ping_period(clock_division_ratio);
+
+	pm_runtime_enable(&pdev->dev);
+
 	rc = watchdog_register_device(&sh_wdt_dev);
 	if (unlikely(rc)) {
 		dev_err(&pdev->dev, "Can't register watchdog (err=%d)\n", rc);
+		pm_runtime_disable(&pdev->dev);
 		return rc;
 	}
 
-	timer_setup(&wdt->timer, sh_wdt_ping, 0);
-	wdt->timer.expires	= next_ping_period(clock_division_ratio);
-
 	dev_info(&pdev->dev, "initialized.\n");
 
-	pm_runtime_enable(&pdev->dev);
-
 	return 0;
 }
 
-- 
2.25.1