Some Coffee Lake platforms have skewed HPET timer once the SoCs entered PC10, and marked TSC as unstable clocksource as result.
Harry Pan identified it's a firmware bug [1].
To prevent creating a circular dependency between HPET and TSC, let's disable HPET on affected platforms.
[1]: https://lore.kernel.org/lkml/20190516090651.1396-1-harry.pan@intel.com/ Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203183
Cc: stable@vger.kernel.org Suggested-by: Feng Tang feng.tang@intel.com Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com --- arch/x86/kernel/early-quirks.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c index 6f6b1d04dadf..4cba91ec8049 100644 --- a/arch/x86/kernel/early-quirks.c +++ b/arch/x86/kernel/early-quirks.c @@ -710,6 +710,8 @@ static struct chipset early_qrk[] __initdata = { */ { PCI_VENDOR_ID_INTEL, 0x0f00, PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet}, + { PCI_VENDOR_ID_INTEL, 0x3ec4, + PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet}, { PCI_VENDOR_ID_BROADCOM, 0x4331, PCI_CLASS_NETWORK_OTHER, PCI_ANY_ID, 0, apple_airport_reset}, {}