x86/quirks: Disable HPET on Intel Coffe Lake platforms

Some Coffee Lake platforms have a skewed HPET timer once the SoCs entered PC10, which in consequence marks TSC as unstable because HPET is used as watchdog clocksource for TSC. Harry Pan tried to work around it in the clocksource watchdog code [1] thereby creating a circular dependency between HPET and TSC. This also ignores the fact, that HPET is not only unsuitable as watchdog clocksource on these systems, it becomes unusable in general. Disable HPET on affected platforms. Suggested-by: Feng Tang <[email protected]> Signed-off-by: Kai-Heng Feng <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Cc: [email protected] Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203183 Link: https://lore.kernel.org/lkml/[email protected]/ [1] Link: https://lkml.kernel.org/r/[email protected]
voipac · Nov 12, 2019 · fc5db58 · fc5db58
1 parent 31f4f5b
commit fc5db58
Showing 1 changed file with 2 additions and 0 deletions.
diff --git 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},
 	{}