Re: [PATCH v3 0/6] clocksource: rework Atmel TCB timer driver

From: Alexandre Belloni
Date: Thu Mar 29 2018 - 07:43:00 EST


On 29/03/2018 at 13:31:18 +0200, Alexander Dahl wrote:
> Pretty sure. I rebuilt the whole BSP and added another line to the kernel
> source to see if the tree I applied the patches to, was actually built:
>
>
> diff --git a/drivers/clocksource/timer-atmel-tcb.c b/drivers/clocksource/timer-atmel-tcb.c
> index 7fde9cfbf203..f85affc74a86 100644
> --- a/drivers/clocksource/timer-atmel-tcb.c
> +++ b/drivers/clocksource/timer-atmel-tcb.c
> @@ -222,7 +222,8 @@ 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);
> + pr_info( "*** bits: 0x%x, BIT(bits): 0x%lx\n", bits, BIT(bits) );
> + 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);
>
>

I've just tested on a g20, old driver:
INT NAME RATE MAX
16 [vel at91_tick,] 175 Ints/s (max: 231)
19 [ vel tc_clkevt] 129 Ints/s (max: 129)


new driver:
INT NAME RATE MAX
17 [vel timer@fffa] 129 Ints/s (max: 129)
18 [ vel ttyS0] 175 Ints/s (max: 231)


--
Alexandre Belloni, Bootlin (formerly Free Electrons)
Embedded Linux and Kernel engineering
https://bootlin.com