4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Len Brown <[email protected]>


[ Upstream commit 695085b4bc7603551db0b3da897b8bf9893ca218 ]

The Intel Denverton microserver uses a 25 MHz TSC crystal,
so we can derive its exact [*] TSC frequency
using CPUID and some arithmetic, eg.:

  TSC: 1800 MHz (25000000 Hz * 216 / 3 / 1000000)

[*] 'exact' is only as good as the crystal, which should be +/- 20ppm

Signed-off-by: Len Brown <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: 
http://lkml.kernel.org/r/306899f94804aece6d8fa8b4223ede3b48dbb59c.1484287748.git.len.br...@intel.com
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 arch/x86/kernel/tsc.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -694,6 +694,7 @@ unsigned long native_calibrate_tsc(void)
                        crystal_khz = 24000;    /* 24.0 MHz */
                        break;
                case INTEL_FAM6_SKYLAKE_X:
+               case INTEL_FAM6_ATOM_DENVERTON:
                        crystal_khz = 25000;    /* 25.0 MHz */
                        break;
                case INTEL_FAM6_ATOM_GOLDMONT:


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