From bbaf0afc9b28644b357f284ad27c9e40e015d2de Mon Sep 17 00:00:00 2001 From: Koen Kooi Date: Fri, 20 Jun 2008 12:27:02 +0000 Subject: linux omap2 git: add patch to surpress spurious timer reprogramming --- .../beagleboard/timer-suppression.patch | 43 ++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 packages/linux/linux-omap2-git/beagleboard/timer-suppression.patch (limited to 'packages/linux/linux-omap2-git/beagleboard') diff --git a/packages/linux/linux-omap2-git/beagleboard/timer-suppression.patch b/packages/linux/linux-omap2-git/beagleboard/timer-suppression.patch new file mode 100644 index 0000000000..04362c96e3 --- /dev/null +++ b/packages/linux/linux-omap2-git/beagleboard/timer-suppression.patch @@ -0,0 +1,43 @@ +diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c +index b854a89..26f5569 100644 +--- a/kernel/time/tick-sched.c ++++ b/kernel/time/tick-sched.c +@@ -253,6 +253,16 @@ void tick_nohz_stop_sched_tick(void) + + /* Schedule the tick, if we are at least one jiffie off */ + if ((long)delta_jiffies >= 1) { ++ /* ++ * calculate the expiry time for the next timer wheel ++ * timer ++ */ ++ expires = ktime_add_ns(last_update, tick_period.tv64 * ++ delta_jiffies); ++ ++ /* Skip reprogram of event if its not changed */ ++ if(ts->tick_stopped && ktime_equal(expires, dev->next_event)) ++ goto out2; + + if (delta_jiffies > 1) + cpu_set(cpu, nohz_cpu_mask); +@@ -304,12 +314,7 @@ void tick_nohz_stop_sched_tick(void) + goto out; + } + +- /* +- * calculate the expiry time for the next timer wheel +- * timer +- */ +- expires = ktime_add_ns(last_update, tick_period.tv64 * +- delta_jiffies); ++ /* Mark expiries */ + ts->idle_expires = expires; + + if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { +@@ -328,6 +333,7 @@ void tick_nohz_stop_sched_tick(void) + tick_do_update_jiffies64(ktime_get()); + cpu_clear(cpu, nohz_cpu_mask); + } ++out2: + raise_softirq_irqoff(TIMER_SOFTIRQ); + out: + ts->next_jiffies = next_jiffies; -- cgit v1.2.3