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x86: disable hpet on shutdown 

If HPET was enabled by pci quirks, we use i8253 as initial clockevent
because pci quirks doesn't run until pci is initialized.

The above means the kernel (or something) is assuming HPET legacy
replacement is disabled and can use i8253 at boot.

If we used kexec, it isn't true. So, this patch disables HPET legacy
replacement for kexec in machine_shutdown().

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
OGAWA Hirofumi 2007-12-03 17:17:10 +01:00 committed by Ingo Molnar
parent 92d499d991
commit c86c7fbc82
4 changed files with 23 additions and 0 deletions
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14
arch/x86/kernel/hpet.c
View File

@ -446,6 +446,20 @@ static __init int hpet_late_init(void)
}
fs_initcall(hpet_late_init);
void hpet_disable(void)
{
if (is_hpet_capable()) {
unsigned long cfg = hpet_readl(HPET_CFG);
if (hpet_legacy_int_enabled) {
cfg &= ~HPET_CFG_LEGACY;
hpet_legacy_int_enabled = 0;
}
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
}
#ifdef CONFIG_HPET_EMULATE_RTC
/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET

4
arch/x86/kernel/reboot_32.c
View File

@ -11,6 +11,7 @@
#include <linux/reboot.h>
#include <asm/uaccess.h>
#include <asm/apic.h>
#include <asm/hpet.h>
#include <asm/desc.h>
#include "mach_reboot.h"
#include <asm/reboot_fixups.h>
@ -326,6 +327,9 @@ static void native_machine_shutdown(void)
#ifdef CONFIG_X86_IO_APIC
disable_IO_APIC();
#endif
#ifdef CONFIG_HPET_TIMER
hpet_disable();
#endif
}
void __attribute__((weak)) mach_reboot_fixups(void)

4
arch/x86/kernel/reboot_64.c
View File

@ -17,6 +17,7 @@
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/apic.h>
#include <asm/hpet.h>
#include <asm/gart.h>
/*
@ -113,6 +114,9 @@ void machine_shutdown(void)
disable_IO_APIC();
#ifdef CONFIG_HPET_TIMER
hpet_disable();
#endif
local_irq_restore(flags);
pci_iommu_shutdown();

1
include/asm-x86/hpet.h
View File

@ -61,6 +61,7 @@ extern unsigned long force_hpet_address;
extern int hpet_force_user;
extern int is_hpet_enabled(void);
extern int hpet_enable(void);
extern void hpet_disable(void);
extern unsigned long hpet_readl(unsigned long a);
extern void force_hpet_resume(void);