Cc: Arnd Hannemann <hannemann@...>, Jordan Crouse <jordan.crouse@...>, Lars Heete <hel@...>, Andres Salomon <dilinger@...>, Linux Kernel Mailing List <linux-kernel@...>, Thomas Gleixner <tglx@...>, H. Peter Anvin <hpa@...>, Andrew Morton <akpm@...>, Linus Torvalds <torvalds@...>
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 <w@1wt.eu>
---
arch/x86/kernel/mfgpt_32.c | 24 ++++++++++++------------
1 files changed, 12 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/mfgpt_32.c b/arch/x86/kernel/mfgpt_32.c
index 3960ab7..5519091 100644
--- a/arch/x86/kernel/mfgpt_32.c
+++ b/arch/x86/kernel/mfgpt_32.c
@@ -12,21 +12,21 @@
*/
/*
- * 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:
*
- * 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 +45,7 @@ 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
--
1.5.3.4
--
