Re: [PATCH 1/2] ptp_clock: allow for it to be optional

--- a/include/linux/ptp_clock_kernel.h
+++ b/include/linux/ptp_clock_kernel.h

@@ -207,7 +207,16 @@ int ptp_find_pin(struct ptp_clock *ptp,
 #else
 static inline struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 						   struct device *parent)
-{ return NULL; }
+{
+	if (IS_MODULE(CONFIG_PTP_1588_CLOCK)) {
+		pr_warn("%s is built-in while PTP clock subsystem is modular, "
+			"PTP clock ignored\n", KBUILD_MODNAME);
+	} else {
+		pr_warn("ignoring PTP clock from %s as PTP clock subsystem "
+			"is configured out\n", KBUILD_MODNAME);
+	}
+	return NULL;
+}