linux/arch/i386/kernel
Thomas Gleixner d36b49b910 [PATCH] i386 rework local apic timer calibration
The local apic timer calibration has two problem cases:

1.  The calibration is based on readout of the PIT/HPET timer to detect the
   wrap of the periodic tick.  It happens that a box gets stuck in the
   calibration loop due to a PIT with a broken readout function.

2.  CoreDuo boxen show a sporadic PIT runs too slow defect, which results
   in a wrong lapic calibration.  The PIT goes back to normal operation once
   the lapic timer is switched to periodic mode.

Both are existing and unfixed problems in the current upstream kernel and
prevent certain laptops and other systems from booting Linux.

Rework the code to address both problems:

- Make the calibration interrupt driven.  This removes the wait_timer_tick
  magic hackery from lapic.c and time_hpet.c.  The clockevents framework
  allows easy substitution of the global tick event handler for the
  calibration.  This is more accurate than monitoring jiffies.  At this point
  of the boot process, nothing disturbes the interrupt delivery, so the
  results are very accurate.

- Verify the calibration against the PM timer, when available by using the
  early access function.  When the measured calibration period is outside of
  an one percent window, then the lapic timer calibration is adjusted to the
  pm timer result.

- Verify the calibration by running the lapic timer with the calibration
  handler.  Disable lapic timer in case of deviation.

This also removes the "synchronization" of the local apic timer to the global
tick.  This synchronization never worked, as there is no way to synchronize
PIT(HPET) and local APIC timer.  The synchronization by waiting for the tick
just alignes the local APIC timer for the first events, but later the events
drift away due to the different clocks.  Removing the "sync" is just
randomizing the asynchronous behaviour at setup time.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-16 08:13:59 -08:00
..
acpi [PATCH] Allow early access to the power management timer 2007-02-16 08:13:58 -08:00
cpu [PATCH] i386: fix 32-bit ioctls on x64_32 2007-02-13 13:26:26 +01:00
.gitignore [PATCH] x86: gitignore some autogenerated files for i386 2006-02-14 16:09:35 -08:00
Makefile [PATCH] clockevents: i386 drivers 2007-02-16 08:13:59 -08:00
alternative.c [PATCH] paravirt: Patch inline replacements for paravirt intercepts 2006-12-07 02:14:08 +01:00
apic.c [PATCH] i386 rework local apic timer calibration 2007-02-16 08:13:59 -08:00
apm.c [PATCH] i386: use GTOD persistent clock support 2007-02-16 08:13:57 -08:00
asm-offsets.c [PATCH] i386: Convert i386 PDA code to use %fs 2007-02-13 13:26:20 +01:00
bootflag.c Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
cpuid.c [PATCH] i386: use smp_call_function_single() 2007-02-13 13:26:23 +01:00
crash.c [PATCH] Kexec / Kdump: Unify elf note code 2006-12-07 08:39:46 -08:00
crash_dump.c [PATCH] kdump: read previous kernel's memory 2006-01-10 08:01:28 -08:00
doublefault.c [PATCH] i386: cpu_relax() in crash.c and doublefault.c 2006-06-25 10:00:55 -07:00
e820.c [PATCH] i386: romsignature/checksum cleanup 2007-02-13 13:26:22 +01:00
early_printk.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
efi.c [PATCH] EFI x86: pass firmware call parameters on the stack 2007-02-04 10:27:10 -08:00
efi_stub.S [PATCH] x86: remove unused include from efi_stub.S 2006-09-26 08:48:56 -07:00
entry.S [PATCH] i386: entry.S END/ENDPROC annotations 2007-02-13 13:26:24 +01:00
head.S [PATCH] i386: Rename cpu_gdt_descr and remove extern declaration from smpboot.c 2007-02-13 13:26:26 +01:00
hpet.c [PATCH] clockevents: i386 drivers 2007-02-16 08:13:59 -08:00
i386_ksyms.c Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
i387.c Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
i8237.c [PATCH] mmc (mainly): add "or later" clause to licence statement. 2006-10-01 00:39:23 -07:00
i8253.c [PATCH] clockevents: i386 drivers 2007-02-16 08:13:59 -08:00
i8259.c [PATCH] clockevents: i386 drivers 2007-02-16 08:13:59 -08:00
init_task.c [PATCH] nsproxy: move init_nsproxy into kernel/nsproxy.c 2006-10-02 07:57:20 -07:00
io_apic.c [PATCH] i386, apic: clean up the APIC code 2007-02-16 08:13:58 -08:00
ioport.c [PATCH] i386: use thread_info flags for debug regs and IO bitmaps 2006-07-09 18:47:12 -07:00
irq.c [PATCH] i386, apic: clean up the APIC code 2007-02-16 08:13:58 -08:00
kprobes.c [PATCH] i386: Kprobe rpl fix 2007-02-13 13:26:21 +01:00
ldt.c [PATCH] i386: remove default_ldt, and simplify ldt-setting. 2006-12-07 02:14:01 +01:00
machine_kexec.c [PATCH] i386: Avoid overwriting the current pgd (V4, i386) 2006-09-26 10:52:38 +02:00
mca.c [PATCH] i386: replace kmalloc+memset with kzalloc 2006-12-07 02:14:19 +01:00
microcode.c [PATCH] i386: Fix warning in microcode.c 2007-02-13 13:26:25 +01:00
module.c [PATCH] Generic BUG for i386 2006-12-08 08:28:39 -08:00
mpparse.c ACPICA: use new ACPI headers. 2007-02-02 21:14:28 -05:00
msr.c [PATCH] i386: use smp_call_function_single() 2007-02-13 13:26:23 +01:00
nmi.c [PATCH] x86: Enable NMI watchdog for AMD Family 0x10 CPUs 2007-02-13 13:26:25 +01:00
numaq.c Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
paravirt.c [PATCH] i386: paravirt unhandled fallthrough 2007-02-13 13:26:26 +01:00
pci-dma.c [PATCH] i386: replace kmalloc+memset with kzalloc 2006-12-07 02:14:19 +01:00
pcspeaker.c [PATCH] x86: Unify pcspeaker platform device code between i386/x86-64 2007-02-13 13:26:26 +01:00
process.c [PATCH] i386: add idle notifier 2007-02-13 13:26:22 +01:00
ptrace.c [PATCH] i386: Convert i386 PDA code to use %fs 2007-02-13 13:26:20 +01:00
quirks.c [PATCH] x86: Fix verify_quirk_intel_irqbalance() 2006-12-09 21:33:35 +01:00
reboot.c [PATCH] arch/i386/kernel/reboot.c should #include <linux/reboot.h> 2006-12-07 08:39:44 -08:00
reboot_fixups.c [PATCH] i386: Remove printk about reboot fixups at reboot 2006-04-09 11:53:53 -07:00
relocate_kernel.S [PATCH] i386: Avoid overwriting the current pgd (V4, i386) 2006-09-26 10:52:38 +02:00
scx200.c Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
setup.c [PATCH] x86: Unify pcspeaker platform device code between i386/x86-64 2007-02-13 13:26:26 +01:00
sigframe.h [PATCH] __user annotations for pointers in i386 sigframe 2005-09-09 10:31:59 -07:00
signal.c [PATCH] x86: Don't require the vDSO for handling a.out signals 2007-02-13 13:26:26 +01:00
smp.c [PATCH] i386: Small cleanup to TLB flush code 2007-02-13 13:26:23 +01:00
smpboot.c [PATCH] clockevents: i386 drivers 2007-02-16 08:13:59 -08:00
srat.c ACPI: build fix for IBM x440 - CONFIG_X86_SUMMIT 2007-02-02 21:47:33 -05:00
summit.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
sys_i386.c [PATCH] provide kernel_execve on all architectures 2006-10-02 07:57:23 -07:00
syscall_table.S [PATCH] epoll_pwait() 2006-10-11 11:14:21 -07:00
sysenter.c [PATCH] i386: Fix broken CONFIG_COMPAT_VDSO on i386 2007-02-13 13:26:26 +01:00
time.c [PATCH] clockevents: i386 drivers 2007-02-16 08:13:59 -08:00
topology.c [PATCH] i386: change the 'no_control' field to 'hotpluggable' in the struct cpu 2006-12-07 02:14:10 +01:00
trampoline.S [PATCH] i386: fix modpost warning in SMP trampoline code 2007-01-05 23:55:23 -08:00
traps.c [PATCH] i386: add option to show more code in oops reports 2007-02-13 13:26:25 +01:00
tsc.c [PATCH] Mark TSC on GeodeLX reliable 2007-02-16 08:13:58 -08:00
tsc_sync.c [PATCH] x86: rewrite SMP TSC sync code 2007-02-16 08:13:57 -08:00
vm86.c [PATCH] i386: Convert i386 PDA code to use %fs 2007-02-13 13:26:20 +01:00
vmi.c [PATCH] i386: vMI timer patches 2007-02-13 13:26:21 +01:00
vmitime.c [PATCH] clocksource: replace is_continuous by a flag field 2007-02-16 08:13:57 -08:00
vmlinux.lds.S [PATCH] i386: move startup_32() in text.head section 2007-02-13 13:26:22 +01:00
vsyscall-int80.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vsyscall-note.S [PATCH] i386 vDSO: add PT_NOTE segment 2005-04-16 15:24:48 -07:00
vsyscall-sigreturn.S [PATCH] Mark unwind info for signal trampolines in vDSOs 2006-03-31 12:18:52 -08:00
vsyscall-sysenter.S [PATCH] vdso: randomize the i386 vDSO by moving it into a vma 2006-06-27 17:32:38 -07:00
vsyscall.S Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
vsyscall.lds.S [PATCH] vDSO hash-style fix 2006-07-31 13:28:43 -07:00