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authorSuresh Siddha <suresh.b.siddha@intel.com>2012-04-09 15:41:44 -0700
committerThomas Gleixner <tglx@linutronix.de>2012-04-10 11:42:07 +0200
commitfa4da365bc7772c2cd6d5405bdf151612455f957 (patch)
treea688173e5ba7428e934dee1ea2905c2bbe92ef50 /kernel
parent9886f444129171569461d8c39983e16f4871e3b4 (diff)
downloadlinux-fa4da365bc7772c2cd6d5405bdf151612455f957.tar.gz
clockevents: tTack broadcast device mode change in tick_broadcast_switch_to_oneshot()
In the commit 77b0d60c5adf39c74039e2142a1d3cd1e4d53799,
"clockevents: Leave the broadcast device in shutdown mode when not needed",
we were bailing out too quickly in tick_broadcast_switch_to_oneshot(),
with out tracking the broadcast device mode change to 'TICKDEV_MODE_ONESHOT'.

This breaks the platforms which need broadcast device oneshot services during
deep idle states. tick_broadcast_oneshot_control() thinks that it is
in periodic mode and fails to take proper decisions based on the
CLOCK_EVT_NOTIFY_BROADCAST_[ENTER, EXIT] notifications during deep
idle entry/exit.

Fix this by tracking the broadcast device mode as 'TICKDEV_MODE_ONESHOT',
before leaving the broadcast HW device in shutdown mode if there are no active
requests for the moment.

Reported-and-tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: johnstul@us.ibm.com
Link: http://lkml.kernel.org/r/1334011304.12400.81.camel@sbsiddha-desk.sc.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/time/tick-broadcast.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index e883f57a3cd3..bf57abdc7bd0 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -575,10 +575,12 @@ void tick_broadcast_switch_to_oneshot(void)
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
+
+	tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT;
+
 	if (cpumask_empty(tick_get_broadcast_mask()))
 		goto end;
 
-	tick_broadcast_device.mode = TICKDEV_MODE_ONESHOT;
 	bc = tick_broadcast_device.evtdev;
 	if (bc)
 		tick_broadcast_setup_oneshot(bc);