svn commit: r191674 - in head/sys/dev/ata: . chipsets

[Alexander Leidinger]

Quoting Alexander Motin <mav at FreeBSD.org> (from Thu, 18 Jun 2009  
16:31:18 +0300):

> Alexander Leidinger wrote:
>> Quoting Alexander Motin <mav at FreeBSD.org> (from Wed, 17 Jun 2009
>> 16:10:25 +0300):
>>
>>> Alexander Leidinger wrote:
>>>> Quoting Alexander Motin <mav at FreeBSD.org> (from Wed, 29 Apr 2009
>>>> 21:17:18 +0000 (UTC)):
>>
>>>>>   PARTIAL state has up to 100us (50us for me) wakeup latency, but
>>>>> for my
>>>>>   ICH8M saves 0.5W of power per drive. SLUMBER state has up to 10ms
>>>>> (3.5ms
>>>>>   for me) wakeup latency, but saves 0.8W of power.
>>>>>
>>>>>   Modes 2 and 3 are implemented only for AHCI driver now.
>>>>
>>>> Does this mean it is for SATA devices only, or is this a feature of the
>>>> complete controller (ICH5 in my case) and also works with PATA drives?
>>>
>>> This feature is SATA-specific by definition. AFAIK there is no bus power
>>> management in PATA.
>>
>> What happens if such a setting is made for a pata channel, will the
>> system ignore it? The idea of the question is: can I just add those
>> hints for all my ata channels on a remote system without getting into
>> trouble?
>
> You can. Nothing happen. It will just set variable that is used only by
> SATA and AHCI code. PATA does not use it.

Ok, thanks! I'm going to try this now.

Bye,
Alexander.

-- 
Creativity is no substitute for knowing what you are doing.

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