From: Imre Deak Date: Mon, 25 Sep 2006 09:41:21 +0000 (+0300) Subject: ARM: OMAP: timer32k: fix tick count calculation when reprogramming X-Git-Tag: v2.6.19-rc1~885^2~18^2~30 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=df51a84d93e776b7481d937ccd60be1b27d320c5;p=linux-2.6 ARM: OMAP: timer32k: fix tick count calculation when reprogramming Reprogramming takes places before putting the CPU into idle mode if the dynamic tick option is enabled. The timer is then set to expire at the next pending timer event. Because some time has already passed since the last reported jiffy we have to wait less than the time specified in jiffies. Also make sure we don't set a load value of 0 whose outcome is unspecified according to the TRM. Signed-off-by: Imre Deak Signed-off-by: Juha Yrjola Signed-off-by: Tony Lindgren --- diff --git a/arch/arm/plat-omap/timer32k.c b/arch/arm/plat-omap/timer32k.c index 281ecc7fcd..f7b4e89de5 100644 --- a/arch/arm/plat-omap/timer32k.c +++ b/arch/arm/plat-omap/timer32k.c @@ -105,6 +105,8 @@ static inline unsigned long omap_32k_timer_read(int reg) static inline void omap_32k_timer_start(unsigned long load_val) { + if (!load_val) + load_val = 1; omap_32k_timer_write(load_val, OMAP1_32K_TIMER_TVR); omap_32k_timer_write(0x0f, OMAP1_32K_TIMER_CR); } @@ -230,7 +232,15 @@ static irqreturn_t omap_32k_timer_interrupt(int irq, void *dev_id, */ void omap_32k_timer_reprogram(unsigned long next_tick) { - omap_32k_timer_start(JIFFIES_TO_HW_TICKS(next_tick, 32768) + 1); + unsigned long ticks = JIFFIES_TO_HW_TICKS(next_tick, 32768) + 1; + unsigned long now = omap_32k_sync_timer_read(); + unsigned long idled = now - omap_32k_last_tick; + + if (idled + 1 < ticks) + ticks -= idled; + else + ticks = 1; + omap_32k_timer_start(ticks); } static struct irqaction omap_32k_timer_irq;