From 20e912680842504ab4633deaa644c2b855ad3d44 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Thu, 1 Sep 2005 12:48:47 +0100 Subject: [PATCH] [ARM] 2863/1: clarify comment in PXA2xx and SA1x00 timer code Patch from Nicolas Pitre Signed-off-by: Nicolas Pitre Signed-off-by: Russell King --- arch/arm/mach-pxa/time.c | 7 ++++--- 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 72b15e9a373..7dad3f1465e 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 0eeb3616ffe..a084b38698c 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 */ -- 2.20.1