tegra RM: Updated tegra idle loop timing (part 2).

Estimated LP2 sleep time based on the duration of current idle sleep
length as specified by the scheduler, instead of using time to the
next interrupt (the latter does not take into account user mode sleep
delays).

Change-Id: I66bde7035fb71dbcb93c50d92e28a276a1cd9466
Reviewed-on: http://git-master/r/1313
Tested-by: Aleksandr Frid <afrid@nvidia.com>
Reviewed-by: Gary King <gking@nvidia.com>

1 files changed, 14 insertions, 23 deletions

diff --git a/arch/arm/mach-tegra/idle-t2.c b/arch/arm/mach-tegra/idle-t2.c
index 0c37b0686f4e..53095c3e5683 100644
--- a/arch/arm/mach-tegra/idle-t2.c
+++ b/arch/arm/mach-tegra/idle-t2.c
@@ -53,7 +53,7 @@ extern struct wake_lock main_wake_lock;
 #define TEMP_SAVE_AREA_SIZE 16
 #define ENABLE_LP2 1
 #define LP2_PADDING_FACTOR	2
-#define LP2_ROUNDTRIP_TIME_US	2500ul
+#define LP2_ROUNDTRIP_TIME_US	2500l
 //Let Max LP2 time wait be 71 min (Almost a wrap around)
 #define LP2_MAX_WAIT_TIME_US	(71*60*1000000ul)
 
@@ -308,7 +308,7 @@ void cpu_ap20_do_idle(void)
 void mach_tegra_idle(void)
 {
 	bool lp2_ok = true;
-	unsigned long sleep_time;
+	s64 sleep_time;
 
 #ifdef CONFIG_WAKELOCK
 	if (!main_wake_lock.flags || has_wake_lock(WAKE_LOCK_IDLE))
@@ -330,40 +330,31 @@ void mach_tegra_idle(void)
 			lp2_ok = false;
 	}
 
-        if (lp2_ok) {
-		unsigned long now, sleep_jiffies;
-
-		now = (unsigned long)get_jiffies_64();
-		sleep_jiffies = get_next_timer_interrupt(now) - now;
-
-		if (sleep_jiffies > 1) {
-			sleep_time = jiffies_to_usecs(sleep_jiffies - 1);
-
-			sleep_time = min_t(unsigned long, sleep_time,
-				LP2_MAX_WAIT_TIME_US);
+	if (lp2_ok) {
+		sleep_time = ktime_to_us(tick_nohz_get_sleep_length());
 
-			if (sleep_time <=
-				(LP2_ROUNDTRIP_TIME_US*LP2_PADDING_FACTOR))
-				lp2_ok = false;
-		} else
+		if (sleep_time <= (LP2_ROUNDTRIP_TIME_US*LP2_PADDING_FACTOR))
 			lp2_ok = false;
 	}
 
 	if (lp2_ok) {
+		unsigned long lp2_time;
+
 		sleep_time -= LP2_ROUNDTRIP_TIME_US;
-		tegra_lp2_set_trigger(sleep_time);
+		tegra_lp2_set_trigger((unsigned long)sleep_time);
 		cpu_ap20_do_lp2();
 		tegra_lp2_set_trigger(0);
 
 		/* add the actual amount of time spent in lp2 to the timers */
-		sleep_time = NV_REGR(s_hRmGlobal, NvRmModuleID_Pmif,
+		lp2_time = NV_REGR(s_hRmGlobal, NvRmModuleID_Pmif,
 			0, APBDEV_PMC_SCRATCH39_0);
-		sleep_time -= NV_REGR(s_hRmGlobal, NvRmModuleID_Pmif,
+		lp2_time -= NV_REGR(s_hRmGlobal, NvRmModuleID_Pmif,
 			0, APBDEV_PMC_SCRATCH38_0);
 
-		// jiffies += usecs_to_jiffies(sleep_time);
-		// jiffies updated by tick_nohz_restart_sched_tick() after exit
-		NvRmPrivSetLp2TimeUS(s_hRmGlobal, sleep_time);
+		NvRmPrivSetLp2TimeUS(s_hRmGlobal, lp2_time);
+
+		/* adjust kernel timers */
+		hrtimer_peek_ahead_timers();
 	} else
 		cpu_ap20_do_idle();