From 9138dccbb9f39f12474554ef93dcc24de2e9c8f6 Mon Sep 17 00:00:00 2001 From: Deepak Saxena Date: Tue, 23 Aug 2005 13:30:29 -0700 Subject: [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 Signed-off-by: Linus Torvalds --- include/asm-arm/arch-ixp4xx/timex.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/asm-arm/arch-ixp4xx/timex.h') diff --git a/include/asm-arm/arch-ixp4xx/timex.h b/include/asm-arm/arch-ixp4xx/timex.h index 38c9d77d372..3745e35cc03 100644 --- 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) -- cgit v1.2.3-70-g09d2