On Thursday, August 29, 2013 12:12:17 AM Colin Cross wrote: > On Wed, Aug 28, 2013 at 11:50 PM, Prashant Gaikwad <pgaikwad@xxxxxxxxxx> wrote: > > On Saturday 24 August 2013 01:15 AM, Colin Cross wrote: > >> > >> Calling cpuidle_enter_state is expected to return with interrupts > >> enabled, but interrupts must be disabled before starting the > >> ready loop synchronization stage. Call local_irq_disable after > >> each call to cpuidle_enter_state for the safe state. > >> > >> CC: stable@xxxxxxxxxxxxxxx > >> Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx> > >> --- > >> drivers/cpuidle/coupled.c | 2 ++ > >> 1 file changed, 2 insertions(+) > >> > >> diff --git a/drivers/cpuidle/coupled.c b/drivers/cpuidle/coupled.c > >> index 2a297f8..db92bcb 100644 > >> --- a/drivers/cpuidle/coupled.c > >> +++ b/drivers/cpuidle/coupled.c > >> @@ -460,6 +460,7 @@ int cpuidle_enter_state_coupled(struct cpuidle_device > >> *dev, > >> } > >> entered_state = cpuidle_enter_state(dev, drv, > >> dev->safe_state_index); > >> + local_irq_disable(); > > > > > > Colin, > > > > There is still some window where irq remains enabled after exiting safe > > state. It may introduce some corner case. > > Instead of this can we pass a parameter to cpuidle_enter_state indicating > > that irq has to be enabled or not after exit from idle state, which would be > > false when entering safe state from coupled idle. > > It's fine for irqs to be enabled when exiting the safe state, in fact > on further inspection this patch isn't strictly necessary at all - we > always enable interrupts inside cpuidle_coupled_clear_pokes soon after > cpuidle_enter_state returns, and then disable them again. It's > probably better to disable interrupts right after cpuidle_enter_state, > it makes sure interrupts are consistently disabled when calling > cpuidle_coupled_set_waiting, cpuidle_coupled_cpus_waiting and > cpuidle_coupled_clear_pokes, although that doesn't matter in the > current implementation. > > Rafael, feel free to drop the stable annotation from this patch. I will, thanks! -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
