PcAtChipsetPkg AcpiTimerLib: Wait 363 ACPI timer counts to get TSC Freq

[mirror_edk2.git] / PcAtChipsetPkg / Library / AcpiTimerLib / DxeAcpiTimerLib.c

diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
index 7f7b0f8f62947712e3a3a3d66df51ddeece1c14a..b141c680fb823c59f08efd624d46a9731b3ff224 100644 (file)
--- a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
@@ -20,13 +20,13 @@
   Calculate TSC frequency.\r
 \r
   The TSC counting frequency is determined by comparing how far it counts\r
-  during a 100us period as determined by the ACPI timer. The ACPI timer is\r
-  used because it counts at a known frequency.\r
-  The TSC is sampled, followed by waiting for ACPI_TIMER_FREQUENCY / 10000\r
-  clocks of the ACPI timer, or 100us. The TSC is then sampled again. The\r
-  difference multiplied by 10000 is the TSC frequency. There will be a small\r
-  error because of the overhead of reading the ACPI timer. An attempt is\r
-  made to determine and compensate for this error.\r
+  during a 101.4 us period as determined by the ACPI timer.\r
+  The ACPI timer is used because it counts at a known frequency.\r
+  The TSC is sampled, followed by waiting 363 counts of the ACPI timer,\r
+  or 101.4 us. The TSC is then sampled again. The difference multiplied by\r
+  9861 is the TSC frequency. There will be a small error because of the\r
+  overhead of reading the ACPI timer. An attempt is made to determine and\r
+  compensate for this error.\r
 \r
   @return The number of TSC counts per second.\r
 \r