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android_kernel_xiaomi_sm8350/arch/x86/kernel
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Thomas Gleixner fbb16e2438 [x86] Fix TSC calibration issues 
Larry Finger reported at http://lkml.org/lkml/2008/9/1/90:
An ancient laptop of mine started throwing errors from b43legacy when
I started using 2.6.27 on it. This has been bisected to commit bfc0f59
"x86: merge tsc calibration".

The unification of the TSC code adopted mostly the 64bit code, which
prefers PMTIMER/HPET over the PIT calibration.

Larrys system has an AMD K6 CPU. Such systems are known to have
PMTIMER incarnations which run at double speed. This results in a
miscalibration of the TSC by factor 0.5. So the resulting calibrated
CPU/TSC speed is half of the real CPU speed, which means that the TSC
based delay loop will run half the time it should run. That might
explain why the b43legacy driver went berserk.

On the other hand we know about systems, where the PIT based
calibration results in random crap due to heavy SMI/SMM
disturbance. On those systems the PMTIMER/HPET based calibration logic
with SMI detection shows better results.

According to Alok also virtualized systems suffer from the PIT
calibration method.

The solution is to use a more wreckage aware aproach than the current
either/or decision.

1) reimplement the retry loop which was dropped from the 32bit code
during the merge. It repeats the calibration and selects the lowest
frequency value as this is probably the closest estimate to the real
frequency

2) Monitor the delta of the TSC values in the delay loop which waits
for the PIT counter to reach zero. If the maximum value is
significantly different from the minimum, then we have a pretty safe
indicator that the loop was disturbed by an SMI.

3) keep the pmtimer/hpet reference as a backup solution for systems
where the SMI disturbance is a permanent point of failure for PIT
based calibration

4) do the loop iteration for both methods, record the lowest value and
decide after all iterations finished.

5) Set a clear preference to PIT based calibration when the result
makes sense.

The implementation does the reference calibration based on
HPET/PMTIMER around the delay, which is necessary for the PIT anyway,
but keeps separate TSC values to ensure the "independency" of the
resulting calibration values.

Tested on various 32bit/64bit machines including Geode 266Mhz, AMD K6
(affected machine with a double speed pmtimer which I grabbed out of
the dump), Pentium class machines and AMD/Intel 64 bit boxen.

Bisected-by:  Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-09-02 20:35:56 -07:00
..
acpi x86: fix i486 suspend to disk CR4 oops 2008-08-18 08:50:19 +02:00
cpu Merge branch 'linus' into x86/urgent 2008-08-25 14:39:12 +02:00
.gitignore arch/x86/kernel/.gitignore: Added vmlinux.lds to .gitignore file because it shouldn't be tracked. 2008-07-10 10:13:51 -07:00
alternative.c x86: fix SMP alternatives: use mutex instead of spinlock, text_poke is sleepable 2008-05-23 21:56:52 +02:00
amd_iommu_init.c x86, AMD IOMMU: initialize dma_ops after sysfs registration 2008-08-15 13:56:56 +02:00
amd_iommu.c x86 iommu: remove unneeded parenthesis 2008-08-19 02:16:24 +02:00
aperture_64.c x86: make only GART code include gart.h 2008-07-11 11:00:54 +02:00
apic_32.c x86: resurrect proper handling of maxcpus= kernel option (v2) 2008-08-14 11:18:08 +02:00
apic_64.c x86: resurrect proper handling of maxcpus= kernel option (v2) 2008-08-14 11:18:08 +02:00
apm_32.c remove include/linux/pm_legacy.h 2008-07-24 10:47:22 -07:00
asm-offsets_32.c x86/paravirt: split sysret and sysexit 2008-07-08 13:13:15 +02:00
asm-offsets_64.c xen64: add asm-offsets 2008-07-16 10:58:55 +02:00
asm-offsets.c
audit_64.c
bios_uv.c x86 BIOS interface for RTC on SGI UV 2008-07-18 14:35:14 +02:00
bootflag.c
cpuid.c x86: cpuid: correct return value on partial operations 2008-08-25 17:46:12 -07:00
crash_dump_32.c
crash_dump_64.c
crash.c
doublefault_32.c
ds.c
e820.c x86: introduce x86_quirks 2008-07-20 09:18:17 +02:00
early_printk.c x86, generic: mark early_printk as asmlinkage 2008-06-18 13:11:01 +02:00
early-quirks.c Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', 'x86/core', 'x86/cpu', 'x86/fixmap', 'x86/gart', 'x86/kprobes', 'x86/memtest', 'x86/modules', 'x86/nmi', 'x86/pat', 'x86/reboot', 'x86/setup', 'x86/step', 'x86/unify-pci', 'x86/uv', 'x86/xen' and 'xen-64bit' into x86/for-linus 2008-07-21 16:37:17 +02:00
efi_32.c x86: fix i486 suspend to disk CR4 oops 2008-08-18 08:50:19 +02:00
efi_64.c x86: add flags parameter to reserve_bootmem_generic() 2008-07-08 11:49:49 +02:00
efi_stub_32.S
efi_stub_64.S
efi.c x86: introduce max_low_pfn_mapped for 64-bit 2008-07-11 10:24:04 +02:00
entry_32.S i386 syscall audit fast-path 2008-07-23 18:00:30 -07:00
entry_64.S x86_64 ia32 syscall audit fast-path 2008-07-23 17:55:22 -07:00
ftrace.c ftrace: store mcount address in rec->ip 2008-06-23 22:10:56 +02:00
genapic_64.c GRU Driver: export is_uv_system(), zap_page_range() & follow_page() 2008-07-30 09:41:48 -07:00
genapic_flat_64.c NR_CPUS: Replace NR_CPUS in arch/x86/kernel/genapic_flat_64.c 2008-07-20 10:21:10 +02:00
genx2apic_uv_x.c x86: fix section mismatch warning - uv_cpu_init 2008-08-22 14:12:20 +02:00
geode_32.c x86, geode: add a VSA2 ID for General Software 2008-06-19 14:19:03 +02:00
head32.c x86: extract common part of head32.c and head64.c into head.c 2008-06-05 15:10:02 +02:00
head64.c x86-64: fix overlap of modules and fixmap areas 2008-08-15 17:31:50 +02:00
head_32.S x86: fix cpu hotplug on 32bit 2008-07-27 21:43:11 +02:00
head_64.S Revert "x86_64: there's no need to preallocate level1_fixmap_pgt" 2008-07-16 11:07:30 +02:00
head.c x86: move reserve_setup_data to setup.c 2008-07-08 13:16:14 +02:00
hpet.c x86: hpet: workaround SB700 BIOS 2008-08-14 13:23:45 +02:00
i386_ksyms_32.c ftrace: store mcount address in rec->ip 2008-06-23 22:10:56 +02:00
i387.c x86 ptrace: fix PTRACE_GETFPXREGS error 2008-07-01 11:03:31 +02:00
i8237.c
i8253.c
i8259.c i8259: fix final ugliness 2008-06-02 11:55:52 +02:00
init_task.c [PATCH] take init_files to fs/file.c 2008-05-16 17:22:20 -04:00
io_apic_32.c x86: Restore proper vector locking during cpu hotplug 2008-08-11 10:37:34 +02:00
io_apic_64.c x86: Restore proper vector locking during cpu hotplug 2008-08-11 10:37:34 +02:00
io_delay.c x86: io delay - add checking for NULL early param 2008-07-09 13:57:54 +02:00
ioport.c
ipi.c x86: APIC: remove apic_write_around(); use alternatives 2008-07-18 12:51:21 +02:00
irq_32.c x86: use __page_aligned_data/bss 2008-07-16 10:54:39 +02:00
irq_64.c x86: make /proc/stat account for all interrupts 2008-05-25 07:11:49 +02:00
irqinit_32.c x86: rename the i8259_32/64.c leftovers to irqinit_32/64.c 2008-05-24 16:47:39 +02:00
irqinit_64.c x86-64: make BUILD_IRQ() also reset section back 2008-07-24 12:49:26 -07:00
k8.c
kdebugfs.c x86: Add a arch directory for x86 under debugfs 2008-07-18 17:22:04 -07:00
kgdb.c
kprobes.c kprobes: improve kretprobe scalability with hashed locking 2008-07-25 10:53:30 -07:00
kvm.c
kvmclock.c x86: KVM guest: make kvm_smp_prepare_boot_cpu() static 2008-07-20 12:42:37 +03:00
ldt.c cpumask: change cpumask_of_cpu_ptr to use new cpumask_of_cpu 2008-07-26 16:40:33 +02:00
machine_kexec_32.c kexec jump: fix for ftrace 2008-08-15 08:35:43 -07:00
machine_kexec_64.c kexec jump 2008-07-26 12:00:04 -07:00
Makefile Merge branch 'x86/paravirt-spinlocks' into x86/for-linus 2008-07-21 16:45:56 +02:00
mca_32.c
mfgpt_32.c x86, geode-mfgpt: check IRQ before using MFGPT as clocksource 2008-08-15 17:12:32 +02:00
microcode.c cpumask: change cpumask_of_cpu_ptr to use new cpumask_of_cpu 2008-07-26 16:40:33 +02:00
mmconf-fam10h_64.c x86: mmconf: fix section mismatch warning 2008-08-18 07:49:06 +02:00
module_32.c
module_64.c PAGE_ALIGN(): correctly handle 64-bit values on 32-bit architectures 2008-07-24 10:47:21 -07:00
mpparse.c x86: mpparse.c: fix section mismatch warning 2008-08-18 07:49:26 +02:00
msr.c x86: msr: correct return value on partial operations 2008-08-25 17:46:12 -07:00
nmi.c x86, nmi: clean UP NMI watchdog failure message 2008-08-15 15:35:31 +02:00
numaq_32.c x86: fix BUG: unable to handle kernel paging request (numaq_tsc_disable) 2008-08-21 12:52:01 +02:00
olpc.c
paravirt_patch_32.c x86/paravirt: split sysret and sysexit 2008-07-08 13:13:15 +02:00
paravirt_patch_64.c x86/paravirt: add sysret/sysexit pvops for returning to 32-bit compatibility userspace 2008-07-08 13:15:52 +02:00
paravirt.c x86: export pv_lock_ops non-GPL 2008-08-21 12:42:23 +02:00
pci-calgary_64.c x86: use WARN() in arch/x86/kernel 2008-08-21 10:01:52 +02:00
pci-dma.c generic, x86: fix add iommu_num_pages helper function 2008-07-29 12:12:48 +02:00
pci-gart_64.c Merge branch 'x86/iommu' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip into for-linus 2008-07-28 14:31:10 -07:00
pci-nommu.c dma-mapping: add the device argument to dma_mapping_error() 2008-07-26 12:00:03 -07:00
pci-swiotlb_64.c dma-mapping: add the device argument to dma_mapping_error() 2008-07-26 12:00:03 -07:00
pcspeaker.c
pmtimer_64.c
probe_roms_32.c x86: seperate probe_roms into another file 2008-07-08 12:50:05 +02:00
process_32.c x86: invalidate caches before going into suspend 2008-08-15 14:04:30 +02:00
process_64.c x86: invalidate caches before going into suspend 2008-08-15 14:04:30 +02:00
process.c Merge branches 'x86/urgent', 'x86/amd-iommu', 'x86/apic', 'x86/cleanups', 'x86/core', 'x86/cpu', 'x86/fixmap', 'x86/gart', 'x86/kprobes', 'x86/memtest', 'x86/modules', 'x86/nmi', 'x86/pat', 'x86/reboot', 'x86/setup', 'x86/step', 'x86/unify-pci', 'x86/uv', 'x86/xen' and 'xen-64bit' into x86/for-linus 2008-07-21 16:37:17 +02:00
ptrace.c x86 ptrace: user-sets-TF nits 2008-07-16 12:15:17 -07:00
pvclock.c x86: Add structs and functions for paravirt clocksource 2008-06-24 21:02:31 +03:00
quirks.c Merge branch 'timers/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-15 10:39:57 -07:00
reboot_fixups_32.c x86: constify data in reboot.c 2008-05-25 08:58:30 +02:00
reboot.c cpumask: change cpumask_of_cpu_ptr to use new cpumask_of_cpu 2008-07-26 16:40:33 +02:00
relocate_kernel_32.S kexec jump: check code size in control page 2008-08-15 08:35:42 -07:00
relocate_kernel_64.S
rtc.c provide rtc_cmos platform device 2008-06-12 18:05:42 -07:00
scx200_32.c
setup_percpu.c cpu masks: optimize and clean up cpumask_of_cpu() 2008-07-28 22:20:41 +02:00
setup.c x86: fix VMI for early params 2008-08-22 08:01:54 +02:00
sigframe.h
signal_32.c Merge branch 'sched/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-23 19:36:53 -07:00
signal_64.c x64, fpu: fix possible FPU leakage in error conditions 2008-07-26 16:37:04 +02:00
smp.c generic-ipi: fixlet 2008-07-06 14:01:50 +02:00
smpboot.c x86: fix section mismatch warning - uv_cpu_init 2008-08-22 14:12:20 +02:00
smpcommon.c x86: change init_gdt to update the gdt via write_gdt, rather than a direct write. 2008-08-15 19:16:05 +02:00
stacktrace.c stacktrace: fix modular build, export print_stack_trace and save_stack_trace 2008-06-30 09:20:55 +02:00
step.c x86 ptrace: user-sets-TF nits 2008-07-16 12:15:17 -07:00
summit_32.c x86: make generic arch support NUMAQ 2008-06-10 11:34:42 +02:00
sys_i386_32.c x86: coding style fixes to arch/x86/kernel/sys_i386_32.c 2008-06-10 12:34:54 +02:00
sys_x86_64.c
syscall_64.c
syscall_table_32.S flag parameters add-on: remove epoll_create size param 2008-07-24 10:47:29 -07:00
tce_64.c
test_nx.c
test_rodata.c
time_32.c x86: add ->pre_time_init to x86_quirks 2008-07-20 09:25:52 +02:00
time_64.c x86: merge tsc_init and clocksource code 2008-07-09 07:43:27 +02:00
tlb_32.c on_each_cpu(): kill unused 'retry' parameter 2008-06-26 11:24:38 +02:00
tlb_64.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
tlb_uv.c x86, SGI UV: hardcode the TLB flush interrupt system vector 2008-08-20 12:36:03 +02:00
tls.c
tls.h
topology.c
trampoline_32.S
trampoline_64.S
trampoline.c x86: extend e820 ealy_res support 32bit 2008-05-25 10:55:11 +02:00
traps_32.c x86: introducing asm-x86/traps.h 2008-07-18 18:51:57 +02:00
traps_64.c x64, fpu: fix possible FPU leakage in error conditions 2008-07-26 16:37:04 +02:00
tsc_sync.c x86: use WARN() in arch/x86/kernel 2008-08-21 10:01:52 +02:00
tsc.c [x86] Fix TSC calibration issues 2008-09-02 20:35:56 -07:00
verify_cpu_64.S
visws_quirks.c x86: resurrect proper handling of maxcpus= kernel option (v2) 2008-08-14 11:18:08 +02:00
vm86_32.c
vmi_32.c x86: Fix broken VMI in 2.6.27-rc.. 2008-08-08 15:22:02 -07:00
vmiclock_32.c x86: rename paravirtualized TSC functions 2008-07-09 07:43:28 +02:00
vmlinux_32.lds.S kexec jump: check code size in control page 2008-08-15 08:35:42 -07:00
vmlinux_64.lds.S Merge branch 'core/rodata' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2008-07-14 15:28:10 -07:00
vmlinux.lds.S
vsmp_64.c x86: vsmp_64 add missing includes 2008-05-25 08:58:24 +02:00
vsyscall_64.c Merge branch 'generic-ipi' into generic-ipi-for-linus 2008-07-15 21:55:59 +02:00
x8664_ksyms_64.c Merge branch 'auto-ftrace-next' into tracing/for-linus 2008-07-14 16:11:52 +02:00