[Xen-changelog] [xen-unstable] x86: More accurate PIT frequency estimation (1193182Hz)

[Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>]

# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1216629977 -3600
# Node ID 978ffdd19c0f0c8c7dbe6596bf78e6423de8f2e1
# Parent  217c8b6ebfab10a9fe68d3406f7179fc27aec8e7
x86: More accurate PIT frequency estimation (1193182Hz)

In practice this has no impact since variance between crystals will be
substantially greater than 1-2ppm. But we may as well be as accurate
as possible.

From: Dan Magenheimer <dan.magenheimer@xxxxxxxxxx>
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
 xen/arch/x86/i8259.c          |    2 +-
 xen/arch/x86/time.c           |    2 +-
 xen/include/asm-x86/hvm/vpt.h |    2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff -r 217c8b6ebfab -r 978ffdd19c0f xen/arch/x86/i8259.c
--- a/xen/arch/x86/i8259.c      Mon Jul 21 09:42:30 2008 +0100
+++ b/xen/arch/x86/i8259.c      Mon Jul 21 09:46:17 2008 +0100
@@ -411,7 +411,7 @@ void __init init_IRQ(void)
     apic_intr_init();
 
     /* Set the clock to HZ Hz */
-#define CLOCK_TICK_RATE 1193180 /* crystal freq (Hz) */
+#define CLOCK_TICK_RATE 1193182 /* crystal freq (Hz) */
 #define LATCH (((CLOCK_TICK_RATE)+(HZ/2))/HZ)
     outb_p(0x34, PIT_MODE);        /* binary, mode 2, LSB/MSB, ch 0 */
     outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
diff -r 217c8b6ebfab -r 978ffdd19c0f xen/arch/x86/time.c
--- a/xen/arch/x86/time.c       Mon Jul 21 09:42:30 2008 +0100
+++ b/xen/arch/x86/time.c       Mon Jul 21 09:46:17 2008 +0100
@@ -214,7 +214,7 @@ static struct irqaction irq0 = { timer_i
  * Return processor ticks per second / CALIBRATE_FRAC.
  */
 
-#define CLOCK_TICK_RATE 1193180 /* system crystal frequency (Hz) */
+#define CLOCK_TICK_RATE 1193182 /* system crystal frequency (Hz) */
 #define CALIBRATE_FRAC  20      /* calibrate over 50ms */
 #define CALIBRATE_LATCH ((CLOCK_TICK_RATE+(CALIBRATE_FRAC/2))/CALIBRATE_FRAC)
 
diff -r 217c8b6ebfab -r 978ffdd19c0f xen/include/asm-x86/hvm/vpt.h
--- a/xen/include/asm-x86/hvm/vpt.h     Mon Jul 21 09:42:30 2008 +0100
+++ b/xen/include/asm-x86/hvm/vpt.h     Mon Jul 21 09:46:17 2008 +0100
@@ -95,7 +95,7 @@ struct periodic_time {
 };
 
 
-#define PIT_FREQ 1193181
+#define PIT_FREQ 1193182
 #define PIT_BASE 0x40
 
 typedef struct PITState {

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