Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux

clockevents/drivers/dw_apb_timer: Implement ->set_state_oneshot_stopped()

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>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>

authored by

Jisheng Zhang and committed by
Daniel Lezcano
45735326 86d34732

+1
+1
drivers/clocksource/dw_apb_timer.c
··· 264 264 dw_ced->ced.set_state_shutdown = apbt_shutdown; 265 265 dw_ced->ced.set_state_periodic = apbt_set_periodic; 266 266 dw_ced->ced.set_state_oneshot = apbt_set_oneshot; 267 + dw_ced->ced.set_state_oneshot_stopped = apbt_shutdown; 267 268 dw_ced->ced.tick_resume = apbt_resume; 268 269 dw_ced->ced.set_next_event = apbt_next_event; 269 270 dw_ced->ced.irq = dw_ced->timer.irq;