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authorThomas Gleixner <tglx@linutronix.de>2011-02-25 22:34:23 +0100
committerThomas Gleixner <tglx@linutronix.de>2011-02-26 09:45:28 +0100
commit3a142a0672b48a853f00af61f184c7341ac9c99d (patch)
treee84f2647dc2ae71f2e54f2256ebce87624c11d97 /kernel/time/tick-internal.h
parent493f3358cb289ccf716c5a14fa5bb52ab75943e5 (diff)
downloadlinaro-lsk-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-internal.h')
-rw-r--r--kernel/time/tick-internal.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/time/tick-internal.h b/kernel/time/tick-internal.h
index 290eefbc1f6..f65d3a723a6 100644
--- a/kernel/time/tick-internal.h
+++ b/kernel/time/tick-internal.h
@@ -36,6 +36,7 @@ extern void tick_shutdown_broadcast_oneshot(unsigned int *cpup);
extern int tick_resume_broadcast_oneshot(struct clock_event_device *bc);
extern int tick_broadcast_oneshot_active(void);
extern void tick_check_oneshot_broadcast(int cpu);
+bool tick_broadcast_oneshot_available(void);
# else /* BROADCAST */
static inline void tick_broadcast_setup_oneshot(struct clock_event_device *bc)
{
@@ -46,6 +47,7 @@ static inline void tick_broadcast_switch_to_oneshot(void) { }
static inline void tick_shutdown_broadcast_oneshot(unsigned int *cpup) { }
static inline int tick_broadcast_oneshot_active(void) { return 0; }
static inline void tick_check_oneshot_broadcast(int cpu) { }
+static inline bool tick_broadcast_oneshot_available(void) { return true; }
# endif /* !BROADCAST */
#else /* !ONESHOT */
@@ -76,6 +78,7 @@ static inline int tick_resume_broadcast_oneshot(struct clock_event_device *bc)
return 0;
}
static inline int tick_broadcast_oneshot_active(void) { return 0; }
+static inline bool tick_broadcast_oneshot_available(void) { return false; }
#endif /* !TICK_ONESHOT */
/*