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From: Christopher Covington <cov@codeaurora.org>
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Date: Tue, 27 Dec 2016 10:27:25 -0500
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Subject: Re: [Qemu-devel] [PATCH kvm-unit-tests v8 03/10] arm/arm64: add
 some delay routines
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To: Andrew Jones <drjones@redhat.com>, Andre Przywara <andre.przywara@arm.com>
Cc: peter.maydell@linaro.org, kvm@vger.kernel.org, marc.zyngier@arm.com, qemu-devel@nongnu.org, eric.auger@redhat.com, qemu-arm@nongnu.org, pbonzini@redhat.com, alex.bennee@linaro.org, kvmarm@lists.cs.columbia.edu, christoffer.dall@linaro.org

On 12/09/2016 07:15 AM, Andrew Jones wrote:
> On Fri, Dec 09, 2016 at 11:41:06AM +0000, Andre Przywara wrote:
>> Hi,
>>
>> On 08/12/16 17:50, Andrew Jones wrote:
>>> Allow a thread to wait some specified amount of time. Can
>>> specify in cycles, usecs, and msecs.

>>> +++ b/lib/arm/asm/delay.h
>>> @@ -0,0 +1,14 @@
>>> +#ifndef _ASMARM_DELAY_H_
>>> +#define _ASMARM_DELAY_H_
>>> +/*
>>> + * Copyright (C) 2016, Red Hat Inc, Andrew Jones <drjones@redhat.com>
>>> + *
>>> + * This work is licensed under the terms of the GNU LGPL, version 2.
>>> + */
>>> +#include <libcflat.h>
>>> +
>>> +extern void delay(u64 cycles);
>>
>> Nit: Shouldn't this parameter be called "ticks"? Cycles might be a bit
>> misleading, especially since this prototype is the only documentation on
>> this. You might just want to fix this when applying the patches.
> 
> Right or wrong the kernel uses 'cycles' for this function, named
> __timer_delay for arm and __delay for arm64. I guess I prefer
> consistency here.

I too expect timers to tick and CPUs to cycle. The benefit of
parameter-name-precise consistency with the Linux source is not
obvious to me.

Cov

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