From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> commit 1dc2f2b81a6a9895da59f3915760f6c0c3074492 upstream. The hyperv utilities use PTP clock interfaces and should depend a a kconfig symbol such that they will be built as a loadable module or builtin so that linker errors do not happen. Prevents these build errors: ld: drivers/hv/hv_util.o: in function `hv_timesync_deinit': hv_util.c:(.text+0x37d): undefined reference to `ptp_clock_unregister' ld: drivers/hv/hv_util.o: in function `hv_timesync_init': hv_util.c:(.text+0x738): undefined reference to `ptp_clock_register' Fixes: 3716a49a81ba ("hv_utils: implement Hyper-V PTP source") Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Reported-by: kernel test robot <lkp@xxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx> Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> Cc: Stephen Hemminger <sthemmin@xxxxxxxxxxxxx> Cc: Wei Liu <wei.liu@xxxxxxxxxx> Cc: Dexuan Cui <decui@xxxxxxxxxxxxx> Cc: linux-hyperv@xxxxxxxxxxxxxxx Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20211126023316.25184-1-rdunlap@xxxxxxxxxxxxx Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx> Cc: Petr Å tetiar <ynezz@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/hv/Kconfig | 1 + 1 file changed, 1 insertion(+) --- a/drivers/hv/Kconfig +++ b/drivers/hv/Kconfig @@ -14,6 +14,7 @@ config HYPERV_TSCPAGE config HYPERV_UTILS tristate "Microsoft Hyper-V Utilities driver" depends on HYPERV && CONNECTOR && NLS + depends on PTP_1588_CLOCK_OPTIONAL help Select this option to enable the Hyper-V Utilities. Patches currently in stable-queue which might be from rdunlap@xxxxxxxxxxxxx are queue-4.14/hv-utils-add-ptp_1588_clock-to-kconfig-to-fix-build.patch