[B/D/E/Unstable/OEM-B/OEM-OSP1-B] [PATCH 1/2] UBUNTU: SAUCE: x86/intel: Disable HPET on Intel Coffe Lake platforms

[Kai-Heng Feng]

BugLink: https://bugs.launchpad.net/bugs/1840239

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

Signed-off-by: Kai-Heng Feng <kai.heng.feng at 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 58291692aaec..fc9554a799e5 100644
--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -741,6 +741,8 @@ 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},
 	{ PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0, early_pci_clear_msi},
-- 
2.17.1