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

[Jason A. Donenfeld]

Hey Thomas,

Can we perhaps get this into 5.5-rc2?

It'd be nice if Intel could give us a list of SKUs that are affected
(as you asked in another email thread), but barring that, the best we
can do is whack-a-mole like this. I'm typing you this email on the
hardware that this patch addresses.

Jason

On Tue, Dec 3, 2019 at 9:57 PM Jason A. Donenfeld <Jason@xxxxxxxxx> 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@xxxxxxxxx>
> Cc: Feng Tang <feng.tang@xxxxxxxxx>
> Cc: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
>  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