On Wed, Sep 03, 2025 at 07:34:00PM +0000, Hrishabh Rajput via B4 Relay wrote:

+static int gunyah_wdt_call(unsigned long func_id, unsigned long arg1,
+			   unsigned long arg2, struct arm_smccc_res *res)
+{
+	arm_smccc_1_1_smc(func_id, arg1, arg2, res);
+	return gunyah_error_remap(res->a0);
+}
+
+static int gunyah_wdt_start(struct watchdog_device *wdd)
+{
+	struct arm_smccc_res res;
+	unsigned int timeout_ms;
+	unsigned int pretimeout_ms;
+	int ret;
+
+	ret = gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_DISABLE, 0, &res);
+	if (ret)
+		return ret;

When I ran a simple echo test, it failed here on SM8650 with -EINVAL. May be Gunyah
does not allow disabling watchdog when it is not enabled in the first
place. May be something you can check if this is a difference between
8750 vs 8650.

It also points out that your patch needs some prints upon error. Pls
check and update the patch accordingly.

+
+	timeout_ms = wdd->timeout * 1000;
+	pretimeout_ms = wdd->pretimeout * 1000;
+	ret = gunyah_wdt_call(GUNYAH_WDT_SET_TIME,
+			      pretimeout_ms, timeout_ms, &res);
+	if (ret)
+		return ret;
+
+	return gunyah_wdt_call(GUNYAH_WDT_CONTROL, WDT_CTRL_ENABLE, 0, &res);
+}