diff options
| author | Nicolas Pitre | 2005-09-01 12:48:47 +0100 |
|---|---|---|
| committer | Russell King | 2005-09-01 12:48:47 +0100 |
| commit | 20e912680842504ab4633deaa644c2b855ad3d44 (patch) | |
| tree | b92a5c0c287c9a115a43b85f55a818996df5e319 | |
| parent | 5c53ff088cb76dca52bdf2ef36ea63147763f9ea (diff) | |
[ARM] 2863/1: clarify comment in PXA2xx and SA1x00 timer code
Patch from Nicolas Pitre
Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | arch/arm/mach-pxa/time.c | 7 | ||||
| -rw-r--r-- | arch/arm/mach-sa1100/time.c | 17 |
2 files changed, 12 insertions, 12 deletions
diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c index 72b15e9a373a..7dad3f1465e0 100644 --- a/arch/arm/mach-pxa/time.c +++ b/arch/arm/mach-pxa/time.c @@ -91,9 +91,10 @@ pxa_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) /* Loop until we get ahead of the free running timer. * This ensures an exact clock tick count and time accuracy. - * IRQs are disabled inside the loop to ensure coherence between - * lost_ticks (updated in do_timer()) and the match reg value, so we - * can use do_gettimeofday() from interrupt handlers. + * Since IRQs are disabled at this point, coherence between + * lost_ticks(updated in do_timer()) and the match reg value is + * ensured, hence we can use do_gettimeofday() from interrupt + * handlers. * * HACK ALERT: it seems that the PXA timer regs aren't updated right * away in all cases when a write occurs. We therefore compare with diff --git a/arch/arm/mach-sa1100/time.c b/arch/arm/mach-sa1100/time.c index 0eeb3616ffea..a084b38698cf 100644 --- a/arch/arm/mach-sa1100/time.c +++ b/arch/arm/mach-sa1100/time.c @@ -70,15 +70,6 @@ static unsigned long sa1100_gettimeoffset (void) return usec; } -/* - * We will be entered with IRQs enabled. - * - * Loop until we get ahead of the free running timer. - * This ensures an exact clock tick count and time accuracy. - * IRQs are disabled inside the loop to ensure coherence between - * lost_ticks (updated in do_timer()) and the match reg value, so we - * can use do_gettimeofday() from interrupt handlers. - */ static irqreturn_t sa1100_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) { @@ -86,6 +77,14 @@ sa1100_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs) write_seqlock(&xtime_lock); + /* + * Loop until we get ahead of the free running timer. + * This ensures an exact clock tick count and time accuracy. + * Since IRQs are disabled at this point, coherence between + * lost_ticks(updated in do_timer()) and the match reg value is + * ensured, hence we can use do_gettimeofday() from interrupt + * handlers. + */ do { timer_tick(regs); OSSR = OSSR_M0; /* Clear match on timer 0 */ |