Messages in this thread | | | From | Alexander Dahl <> | Subject | Re: [PATCH v3 0/6] clocksource: rework Atmel TCB timer driver | Date | Thu, 29 Mar 2018 10:01:26 +0200 |
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Hei hei,
Am Mittwoch, 28. März 2018, 17:50:33 CEST schrieb Alexandre Belloni: > On 28/03/2018 at 17:31:35 +0200, Alexandre Belloni wrote: > > > Do you have an explanation of why the rate is much higher ? > > > > The core is giving deltas of 31 clocks instead of much more than that, I > > guess I messed up the initialization somewhere. > > I did mess up. > > Alexander, can you test that:
Well, I just did.
> > diff --git a/drivers/clocksource/timer-atmel-tcb.c > b/drivers/clocksource/timer-atmel-tcb.c index 7fde9cfbf203..bbbacf8c46b0 > 100644 > --- a/drivers/clocksource/timer-atmel-tcb.c > +++ b/drivers/clocksource/timer-atmel-tcb.c > @@ -222,7 +222,7 @@ static int __init tc_clkevt_register(struct device_node > *node, goto err_slow; > clk_disable(tce.clk); > > - clockevents_config_and_register(&tce.clkevt, 32768, 1, bits - 1); > + clockevents_config_and_register(&tce.clkevt, 32768, 1, BIT(bits) - 1); > > ret = request_irq(tce.irq, tc_clkevt2_irq, IRQF_TIMER | IRQF_SHARED, > tce.clkevt.name, &tce); > > This will behave exactly the same as before on 16bits TCB and will have > much less interrupts on 32 bits platforms.
This is the result:
INT NAME RATE MAX 17 [vel timer@fffa] 1837 Ints/s (max: 1912) 26 [ vel eth0] 3 Ints/s (max: 11)
This is not much lower than the ~2150 I reported yesterday?
I'm sorry I can just test this on at91sam9g20 currently, I have no understanding of the subsystem, I can't do a decent review.
Greets Alex
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