linux/arch/x86
Len Brown da4ae6c4a0 x86/tsc: Future-proof native_calibrate_tsc()
If the crystal frequency cannot be determined via CPUID(15).crystal_khz or
the built-in table then native_calibrate_tsc() will still set the
X86_FEATURE_TSC_KNOWN_FREQ flag which prevents the refined TSC calibration.

As a consequence such systems use cpu_khz for the TSC frequency which is
incorrect when cpu_khz != tsc_khz resulting in time drift.

Return early when the crystal frequency cannot be retrieved without setting
the X86_FEATURE_TSC_KNOWN_FREQ flag. This ensures that the refined TSC
calibration is invoked.

[ tglx: Steam-blastered changelog. Sigh ]

Fixes: 4ca4df0b7e ("x86/tsc: Mark TSC frequency determined by CPUID as known")
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: Bin Gao <bin.gao@intel.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/0fe2503aa7d7fc69137141fc705541a78101d2b9.1513920414.git.len.brown@intel.com
2018-01-14 12:14:50 +01:00
..
boot Merge branch 'x86/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-31 13:13:56 -08:00
configs x86/unwind: Rename unwinder config options to 'CONFIG_UNWINDER_*' 2017-10-14 10:12:12 +02:00
crypto crypto: salsa20 - fix blkcipher_walk API usage 2017-11-29 16:25:58 +11:00
entry Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-01-03 16:41:07 -08:00
events Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-01-05 12:23:57 -08:00
hyperv Char/Misc patches for 4.15-rc1 2017-11-16 09:10:59 -08:00
ia32 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
include Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-01-05 12:23:57 -08:00
kernel x86/tsc: Future-proof native_calibrate_tsc() 2018-01-14 12:14:50 +01:00
kvm ARM fixes: 2017-12-21 10:44:13 -08:00
lib Merge branch 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-18 08:59:15 -08:00
math-emu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mm Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-01-05 12:23:57 -08:00
net bpf: fix bpf_tail_call() x64 JIT 2017-10-03 16:04:44 -07:00
oprofile Modules updates for v4.15 2017-11-15 13:46:33 -08:00
pci pci-v4.15-fixes-1 2017-12-14 17:02:39 -08:00
platform x86/platform/intel-mid: Revert "Make 'bt_sfi_data' const" 2018-01-08 20:01:44 +01:00
power Merge branch 'WIP.x86-pti.entry-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-18 08:59:15 -08:00
purgatory License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ras License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
realmode x86/realmode: Don't decrypt trampoline area under SEV 2017-11-07 15:35:55 +01:00
tools License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
um Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
video
xen Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-23 11:53:04 -08:00
.gitignore
Kbuild Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-09-07 09:25:15 -07:00
Kconfig Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-12-23 11:53:04 -08:00
Kconfig.cpu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig.debug Merge commit 'upstream-x86-entry' into WIP.x86/mm 2017-12-17 12:58:53 +01:00
Makefile kmemcheck: remove annotations 2017-11-15 18:21:04 -08:00
Makefile_32.cpu License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Makefile.um License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00