[PATCH 4/7] clocksource/cadence_ttc: Adjust interval in clock notifier

Daniel Lezcano daniel.lezcano at linaro.org
Tue Nov 12 11:29:45 EST 2013


On 11/08/2013 10:21 PM, Soren Brinkmann wrote:
> The clockevent has to be reprogrammed if the timer's input
> clock frequency changes and the timer is in periodic mode, in order to
> maintain the correct timer interval.
>
> Signed-off-by: Soren Brinkmann <soren.brinkmann at xilinx.com>
> ---
>   drivers/clocksource/cadence_ttc_timer.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c
> index a92350b55d32..68a336038d8f 100644
> --- a/drivers/clocksource/cadence_ttc_timer.c
> +++ b/drivers/clocksource/cadence_ttc_timer.c
> @@ -338,6 +338,10 @@ static int ttc_rate_change_clockevent_cb(struct notifier_block *nb,
>   		/* update cached frequency */
>   		ttc->freq = ndata->new_rate;
>
> +		if (ttcce->ce.mode == CLOCK_EVT_MODE_PERIODIC)
> +			ttc_set_interval(ttc, DIV_ROUND_CLOSEST(ttc->freq,
> +						PRESCALE * HZ));
> +

Couldn't be racy ?

>   		/* fall through */
>   	}
>   	case PRE_RATE_CHANGE:
>


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