On Mon, 19 Sep 2016, Jiri Benc wrote:
> On Sun, 18 Sep 2016 23:51:09 -0400, Nicolas Pitre wrote:
> > And to make it possible for PTP to be configured out, the select statement
> > in the Kconfig entry for those ethernet drivers is changed from selecting
> > PTP_1588_CLOCK to PTP_1588_CLOCK_SELECTED whose purpose is to indicate the
> > default Kconfig value for the PTP subsystem.
>
> With this patch applied, the user is free to set a NIC driver as built
> in and PTP_1588_CLOCK as a module, right? If so, that would lead to
> non-functional PTP without any warning due to the use of IS_REACHABLE.
> That doesn't sound right. Could easily cause hours of headache to
> someone.
>
> Or is this handled somehow?
I don't see how to remove the ability to select m for PTP_1588_CLOCK
based on (PTP_1588_CLOCK_SELECTED = y).
What about this on top then:
diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h
index 4c29eb8e53..74079b2fcf 100644
--- 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;
+}
static inline int ptp_clock_unregister(struct ptp_clock *ptp)
{ return 0; }
static inline void ptp_clock_event(struct ptp_clock *ptp,
