Commit 6baf3d61 authored Sep 19, 2016 by Prarit Bhargava Committed by Thomas Gleixner Sep 20, 2016

x86/tsc: Add additional Intel CPU models to the crystal quirk list



commit aa297292 ("x86/tsc: Enumerate SKL cpu_khz and tsc_khz via
CPUID") added code to retrieve the crystal and TSC frequency from CPUID
leaves. If the crystal freqency is enumerated as 0,the resulting TSC
frequency is 0 as well. For CPUs with a known fixed crystal frequency a
quirk list is available to set the frequency,

Kabylake and SkylakeX CPUs are missing in the list of CPUs which need this
quirk. Add them so the TSC frequency can be calculated correctly.

[ tglx: Removed the silly default case as the switch() is only invoked when
  	cpu_khz is 0. Massaged changelog. ]

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: Len Brown <len.brown@intel.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/1474289501-31717-3-git-send-email-prarit@redhat.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

parent 655e52d2

arch/x86/kernel/tsc.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -689,8 +689,13 @@ unsigned long native_calibrate_tsc(void)
		switch (boot_cpu_data.x86_model) {
		case INTEL_FAM6_SKYLAKE_MOBILE:
		case INTEL_FAM6_SKYLAKE_DESKTOP:
		case INTEL_FAM6_KABYLAKE_MOBILE:
		case INTEL_FAM6_KABYLAKE_DESKTOP:
		crystal_khz = 24000; /* 24.0 MHz */
		break;
		case INTEL_FAM6_SKYLAKE_X:
		crystal_khz = 25000; /* 25.0 MHz */
		break;
		case INTEL_FAM6_ATOM_GOLDMONT:
		crystal_khz = 19200; /* 19.2 MHz */
		break;

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