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

From: Daniel Lezcano
Date: Thu Mar 29 2018 - 08:07:43 EST


On 29/03/2018 13:42, Alexandre Belloni wrote:
> 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)

Can you give in both platforms how fast the clocksource wraps up ?

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