[tip:timers/urgent] clockevents: tTack broadcast device mode change in tick_broadcast_switch_to_oneshot()
From: tip-bot for Suresh Siddha
Date: Tue Apr 10 2012 - 05:49:45 EST
Commit-ID: fa4da365bc7772c2cd6d5405bdf151612455f957
Gitweb: http://git.kernel.org/tip/fa4da365bc7772c2cd6d5405bdf151612455f957
Author: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
AuthorDate: Mon, 9 Apr 2012 15:41:44 -0700
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Tue, 10 Apr 2012 11:42:07 +0200
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@xxxxxx>
Signed-off-by: Suresh Siddha <suresh.b.siddha@xxxxxxxxx>
Cc: johnstul@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1334011304.12400.81.camel@xxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/time/tick-broadcast.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index e883f57..bf57abd 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);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/