Hello, On 01/12/2013 12:50 PM, Shawn Guo wrote: > The clockevent core is able to figure out the best mult and shift, > calculate min_delta_ns and max_delta_ns, with the necessary info passed > into clockevents_config_and_register(). Use this combined configure > and register function where possible to make the codes less error prone > and gain some positive diff stat. > > Signed-off-by: Shawn Guo <[email protected]> > Cc: Andres Salomon <[email protected]> > Cc: Nicolas Ferre <[email protected]> > Acked-by: Maxime Ripard <[email protected]>
[...]
I just bisected a timer problem down to this commit.
> diff --git a/drivers/clocksource/tcb_clksrc.c
> b/drivers/clocksource/tcb_clksrc.c
> index 32cb929..8a61872 100644
> --- a/drivers/clocksource/tcb_clksrc.c
> +++ b/drivers/clocksource/tcb_clksrc.c
> @@ -157,7 +157,6 @@ static struct tc_clkevt_device clkevt = {
> .name = "tc_clkevt",
> .features = CLOCK_EVT_FEAT_PERIODIC
> | CLOCK_EVT_FEAT_ONESHOT,
> - .shift = 32,
> /* Should be lower than at91rm9200's system timer */
> .rating = 125,
> .set_next_event = tc_next_event,
> @@ -196,13 +195,9 @@ static void __init setup_clkevents(struct atmel_tc *tc,
> int clk32k_divisor_idx)
>
> timer_clock = clk32k_divisor_idx;
>
> - clkevt.clkevt.mult = div_sc(32768, NSEC_PER_SEC, clkevt.clkevt.shift);
> - clkevt.clkevt.max_delta_ns
> - = clockevent_delta2ns(0xffff, &clkevt.clkevt);
> - clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
^^^^^^
With this patch, the "+ 1" gets lost, resulting in a different
"min_delta_ns".
good:
setup_clkevents: shift=32 mult=140737 min=30518 max=1999976422
bad:
setup_clkevents: shift=32 mult=140737 min=30517 max=1999976422
This leads to problems with schedule_delayed_work() with a delay of
"1". These worksqueues seem to be hanging for several seconds. I'll
send a RFC patch.
> clkevt.clkevt.cpumask = cpumask_of(0);
>
> - clockevents_register_device(&clkevt.clkevt);
> + clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
>
> setup_irq(irq, &tc_irqaction);
> }
>
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
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