On Wed, Jan 23, 2008 at 02:22:59PM -0800, H. Peter Anvin wrote:
> Willy Tarreau wrote:
> >Hi Peter,
> >
> >On Wed, Jan 23, 2008 at 01:59:32PM -0800, H. Peter Anvin wrote:
> >>Willy Tarreau wrote:
> >>>The GEODE MFGPT code assumed that 32kHz was 32000 Hz while the boards
> >>>run on a 32.768 kHz digital watch crystal. In practise, it will not
> >>>change the timer's frequency as the skew was only 2.4%, but it
> >>>should provide more accurate intervals.
> >>>- * Divisor Hz Min Delta (S) Max Delta (S)
> >>Seconds are "s", not "S" (S = siemens.)
> >
> >You're quite right. Same as we should write kHz and not Khz. But I'm
> >used to change other people's work and particularly comments the least
> >possible. Do you want an update ?
> >
>
> I much prefer to see this done right. I have a pretty case-sensitive
> brain, it seems.
Oh rest assured that you're not alone. I was smiling reading Andrew's
comments about people who "cnat tpye", and I must admit that I too am
often quite irritated by incorrect case and inverted letters, but I try
to refrain from whining, people say that I do it too much and for nothing :-)
OK, here it comes updated.
Willy
>From 3a314dd5c2a694f5b0a1c1b8b5690ee28f711b5e Mon Sep 17 00:00:00 2001
From: Willy Tarreau <[EMAIL PROTECTED]>
Date: Wed, 23 Jan 2008 23:05:50 +0100
Subject: [PATCH 1/2] x86: GEODE fix MFGPT input clock value
The GEODE MFGPT code assumed that 32kHz was 32000 Hz while the boards
run on a 32.768 kHz digital watch crystal. In practise, it will not
change the timer's frequency as the skew was only 2.4%, but it
should provide more accurate intervals.
Signed-off-by: Willy Tarreau <[EMAIL PROTECTED]>
---
arch/x86/kernel/mfgpt_32.c | 27 +++++++++++++--------------
1 files changed, 13 insertions(+), 14 deletions(-)
diff --git a/arch/x86/kernel/mfgpt_32.c b/arch/x86/kernel/mfgpt_32.c
index 3960ab7..f97e6e3 100644
--- a/arch/x86/kernel/mfgpt_32.c
+++ b/arch/x86/kernel/mfgpt_32.c
@@ -12,21 +12,20 @@
*/
/*
- * We are using the 32Khz input clock - its the only one that has the
+ * We are using the 32.768kHz input clock - its the only one that has the
* ranges we find desirable. The following table lists the suitable
- * divisors and the associated hz, minimum interval
- * and the maximum interval:
+ * divisors and the associated Hz, minimum interval and the maximum interval:
*
- * Divisor Hz Min Delta (S) Max Delta (S)
- * 1 32000 .0005 2.048
- * 2 16000 .001 4.096
- * 4 8000 .002 8.192
- * 8 4000 .004 16.384
- * 16 2000 .008 32.768
- * 32 1000 .016 65.536
- * 64 500 .032 131.072
- * 128 250 .064 262.144
- * 256 125 .128 524.288
+ * Divisor Hz Min Delta (s) Max Delta (s)
+ * 1 32768 .00048828125 2.000
+ * 2 16384 .0009765625 4.000
+ * 4 8192 .001953125 8.000
+ * 8 4096 .00390625 16.000
+ * 16 2048 .0078125 32.000
+ * 32 1024 .015625 64.000
+ * 64 512 .03125 128.000
+ * 128 256 .0625 256.000
+ * 256 128 .125 512.000
*/
#include <linux/kernel.h>
@@ -45,7 +44,7 @@ static struct mfgpt_timer_t {
#define MFGPT_DIVISOR 16
#define MFGPT_SCALE 4 /* divisor = 2^(scale) */
-#define MFGPT_HZ (32000 / MFGPT_DIVISOR)
+#define MFGPT_HZ (32768 / MFGPT_DIVISOR)
#define MFGPT_PERIODIC (MFGPT_HZ / HZ)
#ifdef CONFIG_GEODE_MFGPT_TIMER
--
1.5.3.3
--
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