Commit 9138dccb authored Aug 23, 2005 by Deepak Saxena Committed by Linus Torvalds Aug 23, 2005

[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>

parent d10689b6

include/asm-arm/arch-ixp4xx/timex.h

+4 −2

Original line number	Diff line number	Diff line
		@@ -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)