[PATCH] Fix IXP4xx CLOCK_TICK_RATE

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 <dsaxena@plexity.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Deepak Saxena 2005-08-23 13:30:29 -07:00 committed by Linus Torvalds
parent d10689b68a
commit 9138dccbb9
1 changed files with 4 additions and 2 deletions

View File

@ -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)