Commit 4342f4ac authored by Greg Ungerer's avatar Greg Ungerer Committed by Linus Torvalds
Browse files

m68knommu: fix ColdFire timer off by 1 



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.  Fix that.

Signed-off-by: default avatarPhilippe De Muyter <phdm@macqel.be>
Signed-off-by: default avatarGreg Ungerer <gerg@uclinux.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4a0df2ef

arch/m68knommu/platform/5307/timers.c

+6 −4
Original line number Diff line number Diff line
@@ -62,10 +62,13 @@ void coldfire_tick(void) 


/***************************************************************************/



static int ticks_per_intr;



void coldfire_timer_init(irq_handler_t handler)

{

	__raw_writew(MCFTIMER_TMR_DISABLE, TA(MCFTIMER_TMR));

	__raw_writetrr(((MCF_BUSCLK / 16) / HZ), TA(MCFTIMER_TRR));

	ticks_per_intr = (MCF_BUSCLK / 16) / HZ;

	__raw_writetrr(ticks_per_intr - 1, TA(MCFTIMER_TRR));

	__raw_writew(MCFTIMER_TMR_ENORI | MCFTIMER_TMR_CLK16 |

		MCFTIMER_TMR_RESTART | MCFTIMER_TMR_ENABLE, TA(MCFTIMER_TMR));
@@ -81,11 +84,10 @@ void coldfire_timer_init(irq_handler_t handler) 


unsigned long coldfire_timer_offset(void)

{

	unsigned long trr, tcn, offset;

	unsigned long tcn, offset;



	tcn = __raw_readw(TA(MCFTIMER_TCN));

	trr = __raw_readtrr(TA(MCFTIMER_TRR));

	offset = (tcn * (1000000 / HZ)) / trr;

	offset = ((tcn + 1) * (1000000 / HZ)) / ticks_per_intr;



	/* Check if we just wrapped the counters and maybe missed a tick */

	if ((offset < (1000000 / HZ / 2)) && mcf_timerirqpending(1))

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