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| author | Star Zeng <star.zeng@intel.com> | 2016-08-17 10:08:31 +0800 |
|---|---|---|
| committer | Star Zeng <star.zeng@intel.com> | 2016-08-18 11:01:54 +0800 |
| commit | a012df5ec643a0c08c2b723a02919a5c9373ca74 (patch) | |
| tree | 0f4854b1fdf60840d62fc411a12e6a3403820469 /OvmfPkg | |
| parent | 7503cd70fb864a5663edb121c9b2488b4c69e7f5 (diff) | |
| download | edk2-platforms-a012df5ec643a0c08c2b723a02919a5c9373ca74.tar.xz | |
PcAtChipsetPkg AcpiTimerLib: Wait 363 ACPI timer counts to get TSC Freq
Compute the number of ticks to wait to measure TSC frequency.
Instead of (ACPI_TIMER_FREQUENCY / 10000) = 357 and 357 * 10000 = 3570000,
use 363 * 9861 = 3579543 Hz which is within 2 Hz of ACPI_TIMER_FREQUENCY.
363 counts is a calibration time of 101.4 uS.
The idea comes from Michael and Paolo.
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul A Lohr <paul.a.lohr@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael D Kinney <michael.d.kinney@intel.com>
Diffstat (limited to 'OvmfPkg')
0 files changed, 0 insertions, 0 deletions