[PATCH] rtc: m41t80: clean up watchdog on registration failure

[PATCH] rtc: m41t80: clean up watchdog on registration failure

[Myeonghun Pak]

The watchdog miscdevice and reboot notifier are registered before the RTC
device. If RTC device registration fails, probe returns without undoing
either registration. The remove callback is not called after probe
failure, leaving callbacks tied to a device whose driver failed to bind.
Those callbacks continue to dereference the file-global save_client.

Unregister the notifier and miscdevice before returning the RTC
registration error.

Fixes: 10d0c768cc6d ("rtc: m41t80: fix race conditions")
Cc: stable@vger.kernel.org
Co-developed-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Ijae Kim <ae878000@gmail.com>
Signed-off-by: Myeonghun Pak <mhun512@gmail.com>
---
 drivers/rtc/rtc-m41t80.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/rtc/rtc-m41t80.c b/drivers/rtc/rtc-m41t80.c
--- a/drivers/rtc/rtc-m41t80.c
+++ b/drivers/rtc/rtc-m41t80.c
@@ -1008,8 +1008,15 @@ static int m41t80_probe(struct i2c_client *client)
 #endif
 
 	rc = devm_rtc_register_device(m41t80_data->rtc);
-	if (rc)
+	if (rc) {
+#ifdef CONFIG_RTC_DRV_M41T80_WDT
+		if (m41t80_data->features & M41T80_FEATURE_HT) {
+			unregister_reboot_notifier(&wdt_notifier);
+			misc_deregister(&wdt_dev);
+		}
+#endif
 		return rc;
+	}
 
 	return 0;
 }
-- 
2.50.1