Commit-ID: 695085b4bc7603551db0b3da897b8bf9893ca218 Gitweb: http://git.kernel.org/tip/695085b4bc7603551db0b3da897b8bf9893ca218 Author: Len Brown <[email protected]> AuthorDate: Fri, 13 Jan 2017 01:11:18 -0500 Committer: Ingo Molnar <[email protected]> CommitDate: Sat, 14 Jan 2017 09:30:37 +0100
x86/tsc: Add the Intel Denverton Processor to native_calibrate_tsc() 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]> --- arch/x86/kernel/tsc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index be3a49e..e41af59 100644 --- 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:
