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| author | Thomas Gleixner <tglx@linutronix.de> | 2011-02-25 22:34:23 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2011-02-26 09:45:28 +0100 |
| commit | 3a142a0672b48a853f00af61f184c7341ac9c99d (patch) | |
| tree | e84f2647dc2ae71f2e54f2256ebce87624c11d97 /kernel/time/tick-broadcast.c | |
| parent | 493f3358cb289ccf716c5a14fa5bb52ab75943e5 (diff) | |
| download | linux-3a142a0672b48a853f00af61f184c7341ac9c99d.tar.gz | |
clockevents: Prevent oneshot mode when broadcast device is periodic
When the per cpu timer is marked CLOCK_EVT_FEAT_C3STOP, then we only can switch into oneshot mode, when the backup broadcast device supports oneshot mode as well. Otherwise we would try to switch the broadcast device into an unsupported mode unconditionally. This went unnoticed so far as the current available broadcast devices support oneshot mode. Seth unearthed this problem while debugging and working around an hpet related BIOS wreckage. Add the necessary check to tick_is_oneshot_available(). Reported-and-tested-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <alpine.LFD.2.00.1102252231200.2701@localhost6.localdomain6> Cc: stable@kernel.org # .21 ->
Diffstat (limited to 'kernel/time/tick-broadcast.c')
| -rw-r--r-- | kernel/time/tick-broadcast.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 48b2761b5668..a3b5aff62606 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -600,4 +600,14 @@ int tick_broadcast_oneshot_active(void) return tick_broadcast_device.mode == TICKDEV_MODE_ONESHOT; } +/* + * Check whether the broadcast device supports oneshot. + */ +bool tick_broadcast_oneshot_available(void) +{ + struct clock_event_device *bc = tick_broadcast_device.evtdev; + + return bc ? bc->features & CLOCK_EVT_FEAT_ONESHOT : false; +} + #endif |