[PATCH net-next] ptp: Remove 'default y' for VMCLOCK PTP device

From: David Woodhouse <[email protected]>

The VMCLOCK device gives support for accurate timekeeping even across 
live migration, unlike the KVM PTP clock. To help ensure that users can
always use ptp_vmclock where it's available in preference to ptp_kvm,
set it to 'default PTP_1588_CLOCK_VMCLOCK' instead of 'default y'.

Signed-off-by: David Woodhouse <[email protected]>
---
 drivers/ptp/Kconfig | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
index e98c9767e0ef..ed087ae75f0e 100644
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -135,12 +135,16 @@ config PTP_1588_CLOCK_VMCLOCK
 	tristate "Virtual machine PTP clock"
 	depends on X86_TSC || ARM_ARCH_TIMER
 	depends on PTP_1588_CLOCK && ACPI && ARCH_SUPPORTS_INT128
-	default y
+	default PTP_1588_CLOCK_KVM
 	help
 	  This driver adds support for using a virtual precision clock
 	  advertised by the hypervisor. This clock is only useful in virtual
 	  machines where such a device is present.
 
+	  Unlike the KVM virtual PTP clock, the VMCLOCK device offers support
+	  for reliable timekeeping even across live migration. So this driver
+	  is enabled by default whenever the KVM PTP clock is.
+
 	  To compile this driver as a module, choose M here: the module
 	  will be called ptp_vmclock.
 
-- 
2.44.0