[PATCH 4.19 024/422] x86/quirks: Disable HPET on Intel Coffe Lake platforms

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>

commit fc5db58539b49351e76f19817ed1102bf7c712d0 upstream.

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@xxxxxxxxx>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=203183
Link: https://lore.kernel.org/lkml/20190516090651.1396-1-harry.pan@xxxxxxxxx/ [1]
Link: https://lkml.kernel.org/r/20191016103816.30650-1-kai.heng.feng@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 arch/x86/kernel/early-quirks.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/x86/kernel/early-quirks.c
+++ b/arch/x86/kernel/early-quirks.c
@@ -707,6 +707,8 @@ static struct chipset early_qrk[] __init
 	 */
 	{ 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},
 	{}





[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux