Commit 6c38d857 authored by Philippe De Muyter's avatar Philippe De Muyter Committed by Linus Torvalds

m68knommu: init coldfire timer TRR with n - 1, not n

The coldfire timer must be initialised to n - 1 if we want it to count n
cycles between each tick interrupt.  This was already fixed, but has been
lost with the conversion to GENERIC_TIMER.
Signed-off-by: default avatarPhilippe De Muyter <phdm@macqel.be>
Acked-by: default avatarGreg Ungerer <gerg@snapgear.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 67dddaad
......@@ -111,7 +111,13 @@ void hw_timer_init(void)
__raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR));
mcftmr_cycles_per_jiffy = FREQ / HZ;
__raw_writetrr(mcftmr_cycles_per_jiffy, TA(MCFTIMER_TRR));
/*
* The coldfire timer runs from 0 to TRR included, then 0
* again and so on. It counts thus actually TRR + 1 steps
* for 1 tick, not TRR. So if you want n cycles,
* initialize TRR with n - 1.
*/
__raw_writetrr(mcftmr_cycles_per_jiffy - 1, TA(MCFTIMER_TRR));
__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |
MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR));
......
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