Messages in this thread | | | Date | Thu, 29 Mar 2018 12:45:42 +0200 | From | Alexandre Belloni <> | Subject | Re: [PATCH v3 0/6] clocksource: rework Atmel TCB timer driver |
| |
On 29/03/2018 at 10:01:26 +0200, Alexander Dahl wrote: > 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.
Hum, are you sure, I went from:
INT NAME RATE MAX 16 [evel timer@fc0] 1027 Ints/s (max: 1028) 21 [ evel at_xdmac] 3 Ints/s (max: 3) 30 [ evel ttyS0] 2 Ints/s (max: 2)
to:
INT NAME RATE MAX 16 [evel timer@fc0] 6 Ints/s (max: 9) 21 [ evel at_xdmac] 2 Ints/s (max: 2) 30 [ evel ttyS0] 2 Ints/s (max: 2)
-- Alexandre Belloni, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering https://bootlin.com
| |