* Feng Tang <feng.t...@intel.com> wrote:
> Hi All,
>
> Please help to review this RFC patch, if you are ok with it. I'll separte
> them into
> 2 and repost.
> 1. make the boot_hpet_disable extern
> 2. add quirk for baytrail HPET.
> thanks!
>
> - Feng
>
>
>
> From 4b8c370649f1d2b320aa46a005b8b61eb59a539e Mon Sep 17 00:00:00 2001
> From: Feng Tang <feng.t...@intel.com>
> Date: Fri, 18 Apr 2014 15:43:22 +0800
> Subject: [PATCH] x86, hpet: Add quirk to disable HPET for baytrail platform
>
> HPET on current baytrail platform has accuracy problem to be used as
> reliable clocksource/clockevent, so add a early quirk to disable it.
>
> Signed-off-by: Feng Tang <feng.t...@intel.com>
> ---
> arch/x86/include/asm/hpet.h | 1 +
> arch/x86/kernel/early-quirks.c | 14 ++++++++++++++
> arch/x86/kernel/hpet.c | 2 +-
> 3 files changed, 16 insertions(+), 1 deletions(-)
>
> diff --git a/arch/x86/include/asm/hpet.h b/arch/x86/include/asm/hpet.h
> index b18df57..36f7125 100644
> --- a/arch/x86/include/asm/hpet.h
> +++ b/arch/x86/include/asm/hpet.h
> @@ -63,6 +63,7 @@
> /* hpet memory map physical address */
> extern unsigned long hpet_address;
> extern unsigned long force_hpet_address;
> +extern int boot_hpet_disable;
> extern u8 hpet_blockid;
> extern int hpet_force_user;
> extern u8 hpet_msi_disable;
> diff --git a/arch/x86/kernel/early-quirks.c b/arch/x86/kernel/early-quirks.c
> index bc4a088..1e5f6bc 100644
> --- a/arch/x86/kernel/early-quirks.c
> +++ b/arch/x86/kernel/early-quirks.c
> @@ -17,6 +17,7 @@
> #include <asm/dma.h>
> #include <asm/io_apic.h>
> #include <asm/apic.h>
> +#include <asm/hpet.h>
> #include <asm/iommu.h>
> #include <asm/gart.h>
> #include <asm/irq_remapping.h>
> @@ -380,6 +381,13 @@ static void __init intel_graphics_stolen(int num, int
> slot, int func)
> }
> }
>
> +static void __init force_disable_hpet(int num, int slot, int func)
> +{
> + boot_hpet_disable = 1;
> + pr_info("Will Disable HPET for this platform\n");
> +}
> +
> +
> #define QFLAG_APPLY_ONCE 0x1
> #define QFLAG_APPLIED 0x2
> #define QFLAG_DONE (QFLAG_APPLY_ONCE|QFLAG_APPLIED)
> @@ -417,6 +425,12 @@ static struct chipset early_qrk[] __initdata = {
> PCI_BASE_CLASS_BRIDGE, 0, intel_remapping_check },
> { PCI_VENDOR_ID_INTEL, PCI_ANY_ID, PCI_CLASS_DISPLAY_VGA, PCI_ANY_ID,
> QFLAG_APPLY_ONCE, intel_graphics_stolen },
> + /*
> + * HPET on current version of Baytrail platform has accuracy
> + * problem, disable it for now
> + */
> + { PCI_VENDOR_ID_INTEL, 0x0f00,
> + PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, force_disable_hpet},
> {}
> };
>
> diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
> index da85a8e..913e207 100644
> --- a/arch/x86/kernel/hpet.c
> +++ b/arch/x86/kernel/hpet.c
> @@ -88,7 +88,7 @@ static inline void hpet_clear_mapping(void)
> /*
> * HPET command line enable / disable
> */
> -static int boot_hpet_disable;
> +int boot_hpet_disable;
> int hpet_force_user;
> static int hpet_verbose;
As long as all those PCI IDs have a buggy HPET, this looks good to me.
hpa, tglx, any preferences?
Thanks,
Ingo
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