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 <feng.tang@intel.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203183
Link: https://lore.kernel.org/lkml/20190516090651.1396-1-harry.pan@intel.com/ [1]
Link: https://lkml.kernel.org/r/20191016103816.30650-1-kai.heng.feng@canonical.com
This commit is contained in:
Kai-Heng Feng 2019-10-16 18:38:16 +08:00 committed by Thomas Gleixner
parent 31f4f5b495
commit fc5db58539
1 changed files with 2 additions and 0 deletions

View File

@ -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},
{}