[tip: x86/urgent] x86/quirks: Disable HPET on Intel Coffe Lake platforms
From: tip-bot2 for Kai-Heng Feng <hidden>
Date: 2019-11-12 15:00:49
Also in:
lkml
Subsystem:
pci subsystem, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Bjorn Helgaas, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
The following commit has been merged into the x86/urgent branch of tip: Commit-ID: fc5db58539b49351e76f19817ed1102bf7c712d0 Gitweb: https://git.kernel.org/tip/fc5db58539b49351e76f19817ed1102bf7c712d0 Author: Kai-Heng Feng [off-list ref] AuthorDate: Wed, 16 Oct 2019 18:38:16 +08:00 Committer: Thomas Gleixner [off-list ref] CommitterDate: Tue, 12 Nov 2019 15:55:20 +01:00 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 <redacted> Signed-off-by: Kai-Heng Feng <redacted> Signed-off-by: Thomas Gleixner <redacted> 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/ (local) [1] Link: https://lkml.kernel.org/r/20191016103816.30650-1-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 6f6b1d0..4cba91e 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}, {}