From: Feng Tang <feng.tang@intel.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Clemens Ladisch <clemens@ladisch.de>,
tglx@linutronix.de, mingo@elte.hu, hpa@zytor.com,
linux-kernel@vger.kernel.org,
John Stultz <john.stultz@linaro.org>,
Andy Lutomirski <luto@amacapital.net>
Subject: Re: [PATCH v2] x86: hpet: Don't default CONFIG_HPET_TIMER to be y for X86_64
Date: Fri, 28 Mar 2014 16:20:54 +0800 [thread overview]
Message-ID: <20140328082054.GB12762@feng-snb> (raw)
In-Reply-To: <20140328081117.GA32308@gmail.com>
On Fri, Mar 28, 2014 at 09:11:17AM +0100, Ingo Molnar wrote:
>
> * Clemens Ladisch <clemens@ladisch.de> wrote:
>
> > Feng Tang wrote:
> > > On Fri, Mar 28, 2014 at 08:17:16AM +0100, Ingo Molnar wrote:
> > >> * Feng Tang <feng.tang@intel.com> wrote:
> > >> - or the kernel should have a quirk to reliably disable it. Why
> > >> should we crash or misbehave if a driver is built into the
> > >> kernel?
> > >
> > > I thought about this before, HPET doesn't have PCI ID like stuff,
> >
> > HPET does have the PCI vendor ID in the first register.
> >
> > > only thing I can think of to identify them may be the CPU family/ID.
> >
> > The HPET is implemented by some actual chip, and that chip also has lots
> > of PCI devices. (In the case of a SoC, the CPU ID would work, too).
>
> Correct. See arch/x86/kernel/hpet.c, which has a large number of HPET
> quirks keyed off chipset PCI IDs:
>
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ESB2_0,
> ich_force_enable_hpet);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_0,
> ich_force_enable_hpet);
> DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_ICH6_1,
> ich_force_enable_hpet);
> [...]
Got it, thanks Ingo and Clemens for the pointer. Will try to figure it out.
- Feng
next prev parent reply other threads:[~2014-03-28 8:21 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-28 2:55 [PATCH v2] x86: hpet: Don't default CONFIG_HPET_TIMER to be y for X86_64 Feng Tang
2014-03-28 7:17 ` Ingo Molnar
2014-03-28 7:37 ` Feng Tang
2014-03-28 8:08 ` Clemens Ladisch
2014-03-28 8:11 ` Ingo Molnar
2014-03-28 8:20 ` Feng Tang [this message]
2014-04-15 7:44 ` Feng Tang
2014-04-15 9:00 ` Ingo Molnar
2014-04-15 9:55 ` Feng Tang
2014-04-15 10:42 ` Ingo Molnar
2014-04-15 14:12 ` Feng Tang
2014-04-16 6:51 ` Ingo Molnar
2014-04-18 7:18 ` Feng Tang
2014-04-18 7:49 ` [RFC PATCH] x86, hpet: Add quirk to disable HPET for baytrail platform Feng Tang
2014-04-18 8:15 ` Ingo Molnar
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