Re: [PATCH] x86/quirks: disable HPET on Intel Coffee Lake Refresh platforms

[Peter Zijlstra <peterz@infradead.org>]

On Fri, Dec 20, 2019 at 02:42:59AM +0100, Jason A. Donenfeld wrote:
> Hi,
> 
> Thought I should give a poke here so that this doesn't slip through
> the cracks again. Could we get this in for rc3?

I think another version of this patch made it in recently, see commit:

  f8edbde885bb ("x86/intel: Disable HPET on Intel Coffee Lake H platforms")

> On Mon, Dec 9, 2019 at 4:45 PM Jason A. Donenfeld <Jason@zx2c4.com> wrote:
> >
> > This is a follow up of fc5db58539b4 ("x86/quirks: Disable HPET on Intel
> > Coffe Lake platforms"), which addressed the issue for 8th generation
> > Coffee Lake. Intel has released Coffee Lake again for 9th generation,
> > apparently still with the same bug:
> >
> > clocksource: timekeeping watchdog on CPU3: Marking clocksource 'tsc' as unstable because the skew is too large:
> > clocksource:                       'hpet' wd_now: 24f422b8 wd_last: 247dea41 mask: ffffffff
> > clocksource:                       'tsc' cs_now: 144d927c4e cs_last: 140ba6e2a0 mask: ffffffffffffffff
> > tsc: Marking TSC unstable due to clocksource watchdog
> > TSC found unstable after boot, most likely due to broken BIOS. Use 'tsc=unstable'.
> > sched_clock: Marking unstable (26553416234, 4203921)<-(26567277071, -9656937)
> > clocksource: Switched to clocksource hpet
> >
> > So, we add another quirk for the chipset
> >
> > Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
> > Cc: Feng Tang <feng.tang@intel.com>
> > Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
> > Cc: Thomas Gleixner <tglx@linutronix.de>
> > Cc: stable@vger.kernel.org
> > ---
> >  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 4cba91ec8049..a73f88dd7f86 100644
> > --- a/arch/x86/kernel/early-quirks.c
> > +++ b/arch/x86/kernel/early-quirks.c
> > @@ -712,6 +712,8 @@ static struct chipset early_qrk[] __initdata = {
> >                 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_INTEL, 0x3e20,
> > +               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},
> >         {}
> > --
> > 2.24.0