On 04/23/2013 03:44 PM, Shawn Guo wrote: > On Tue, Apr 23, 2013 at 03:11:33PM +0200, Marc Kleine-Budde wrote: >> On 04/23/2013 03:08 PM, Marc Kleine-Budde wrote: >>> The commit >>> >>> 77cc982 clocksource: use clockevents_config_and_register() where >>> possible >>> >>> switches from manually calculating min_delta_ns (and others) and >>> clockevents_register_device() to automatic calculation via >>> clockevents_config_and_register(). During this conversation the "+ 1" in >>> >>> min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1; >>> >>> was lost. This leads to problems with schedule_delayed_work() with a delay >>> of >>> "1". Resulting in the work not scheduled in time. >>> >>> This patch fixes the problem by increasing the min_delta to "2" ticks. >>> >>> Signed-off-by: Marc Kleine-Budde <[email protected]> >> >> The problem appears on at91sam9263. This patch successfully fixes the >> problem and applies to current linus/master (post v3.9-rc8). > > Thanks for the fixing, Marc. > > Acked-by: Shawn Guo <[email protected]>
Thanks. The downside of my RFC Patch is, that min_delta_ns is increased
from 30518 to 61035:
good: setup_clkevents: shift=32 mult=140737 min=30518 max=1999976422
bad: setup_clkevents: shift=32 mult=140737 min=30517 max=1999976422
RFC: setup_clkevents: shift=32 mult=140737 min=61035 max=1999976422
To keep the original min_delta_ns value of 30518, a rather hackish
option would be this:
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 8a61872..30e0a68 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -198,6 +198,7 @@ static void __init setup_clkevents(struct atmel_tc *tc, int
clk32k_divisor_idx)
clkevt.clkevt.cpumask = cpumask_of(0);
clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+ clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
setup_irq(irq, &tc_irqaction);
}
Marc
--
Pengutronix e.K. | Marc Kleine-Budde |
Industrial Linux Solutions | Phone: +49-231-2826-924 |
Vertretung West/Dortmund | Fax: +49-5121-206917-5555 |
Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |
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