[PATCH 2.6.13-git] Fix IXP4xx CLOCK_TICK_RATE

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



[RMK is out for the week so sending this direct as it should go into 2.6.13]

As pointed out in the following thread, the CLOCK_TICK_RATE setting for
IXP4xx is incorrect b/c the HW ignores the lowest 2 bits of the LATCH value.

http://lists.arm.linux.org.uk/pipermail/linux-arm-kernel/2005-August/030950.html

Tnx to George Anziger and Egil Hjelmeland for finding the issue.

Signed-off-by: Deepak Saxena <[email protected]>

diff --git a/include/asm-arm/arch-ixp4xx/timex.h b/include/asm-arm/arch-ixp4xx/timex.h
--- a/include/asm-arm/arch-ixp4xx/timex.h
+++ b/include/asm-arm/arch-ixp4xx/timex.h
@@ -7,7 +7,9 @@
 
 /*
  * We use IXP425 General purpose timer for our timer needs, it runs at 
- * 66.66... MHz
+ * 66.66... MHz. We do a convulted calculation of CLOCK_TICK_RATE b/c the
+ * timer register ignores the bottom 2 bits of the LATCH value.
  */
-#define CLOCK_TICK_RATE (66666666)
+#define FREQ 66666666
+#define CLOCK_TICK_RATE (((FREQ / HZ & ~IXP4XX_OST_RELOAD_MASK) + 1) * HZ)
 

-- 
Deepak Saxena - [email protected] - http://www.plexity.net

Even a stopped clock gives the right time twice a day.
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]
  Powered by Linux