| Message ID | 1456479957-1561-1-git-send-email-jszhang@marvell.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 26-02-16, 17:45, Jisheng Zhang wrote: > The dw_apb_timer only "supports PERIODIC mode and their drivers emulate > ONESHOT over that" as described in commit 8fff52fd5093 ("clockevents: > Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state"). > > Inspired by Viresh, I think the dw_apb_timer also needs to implement > the set_state_oneshot_stopped() which is called by the clkevt core, > when the next event is required at an expiry time of 'KTIME_MAX'. This > normally happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes. > > This patch makes the clockevent device to stop on such an event, to > avoid spurious interrupts, as explained by the above commit. > > Signed-off-by: Jisheng Zhang <jszhang@marvell.com> > --- > drivers/clocksource/dw_apb_timer.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/clocksource/dw_apb_timer.c b/drivers/clocksource/dw_apb_timer.c > index 6334526..797505a 100644 > --- a/drivers/clocksource/dw_apb_timer.c > +++ b/drivers/clocksource/dw_apb_timer.c > @@ -264,6 +264,7 @@ dw_apb_clockevent_init(int cpu, const char *name, unsigned rating, > dw_ced->ced.set_state_shutdown = apbt_shutdown; > dw_ced->ced.set_state_periodic = apbt_set_periodic; > dw_ced->ced.set_state_oneshot = apbt_set_oneshot; > + dw_ced->ced.set_state_oneshot_stopped = apbt_shutdown; > dw_ced->ced.tick_resume = apbt_resume; > dw_ced->ced.set_next_event = apbt_next_event; > dw_ced->ced.irq = dw_ced->timer.irq; Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
diff --git a/drivers/clocksource/dw_apb_timer.c b/drivers/clocksource/dw_apb_timer.c index 6334526..797505a 100644 --- a/drivers/clocksource/dw_apb_timer.c +++ b/drivers/clocksource/dw_apb_timer.c @@ -264,6 +264,7 @@ dw_apb_clockevent_init(int cpu, const char *name, unsigned rating, dw_ced->ced.set_state_shutdown = apbt_shutdown; dw_ced->ced.set_state_periodic = apbt_set_periodic; dw_ced->ced.set_state_oneshot = apbt_set_oneshot; + dw_ced->ced.set_state_oneshot_stopped = apbt_shutdown; dw_ced->ced.tick_resume = apbt_resume; dw_ced->ced.set_next_event = apbt_next_event; dw_ced->ced.irq = dw_ced->timer.irq;
The dw_apb_timer only "supports PERIODIC mode and their drivers emulate ONESHOT over that" as described in commit 8fff52fd5093 ("clockevents: Introduce CLOCK_EVT_STATE_ONESHOT_STOPPED state"). Inspired by Viresh, I think the dw_apb_timer also needs to implement the set_state_oneshot_stopped() which is called by the clkevt core, when the next event is required at an expiry time of 'KTIME_MAX'. This normally happens with NO_HZ_{IDLE|FULL} in both LOWRES/HIGHRES modes. This patch makes the clockevent device to stop on such an event, to avoid spurious interrupts, as explained by the above commit. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> --- drivers/clocksource/dw_apb_timer.c | 1 + 1 file changed, 1 insertion(+)