Re: power management on mips

Re: power management on mips

[sjhill]

> Does anyone knows what power management features are there for mips ?
> I know for example that ACPI have been porting to arm. Anything
> equivalent for mips ? Is it possible to do some power management under
> Linux if ACPI or APM is not ported to mips ? And if yes, what would be
> the work to do ?
> 
I have a sudden urge to vomit all over you, maybe because you said
ACPI and MIPS in the same sentence. ACPI is pretty x86-centric. I
doubt it will ever make its way into MIPS. Dan Malek or others may
have comments on various PM schemes used in MIPS. I am surprised
that ARM adopted it, but there's a reason I no longer do ARM kernel
development. ACPI is also a lot of code adding size to your kernel
as well as additional applications. Not really great if your are
doing an embedded system.

-Steve

power management on mips

[Ivan Korzakow]

Hi list,

Does anyone knows what power management features are there for mips ?
I know for example that ACPI have been porting to arm. Anything
equivalent for mips ? Is it possible to do some power management under
Linux if ACPI or APM is not ported to mips ? And if yes, what would be
the work to do ?

Thanks in advance,

Ivan

RE: power management on mips

[Mitchell, Earl]

APM is dead replaced by ACPI which is primarily used for x86 laptops 
I think. While back I read that MontaVista and IBM were working on 
something called Dynamic Power Mgmt (DPM). Might want to check that out? 
See links below. 

-earlm
 
http://www.linuxdevices.com/news/NS4297534594.html
http://tree.celinuxforum.org/CelfPubWiki/PowerManagementDefinitionOfTerms_5fR2
 


> -----Original Message-----
> From: linux-mips-bounce@linux-mips.org
> [mailto:linux-mips-bounce@linux-mips.org]On Behalf Of Ivan Korzakow
> Sent: Tuesday, October 18, 2005 9:01 AM
> To: linux-mips@linux-mips.org
> Subject: power management on mips
> 
> 
> Hi list,
> 
> Does anyone knows what power management features are there for mips ?
> I know for example that ACPI have been porting to arm. Anything
> equivalent for mips ? Is it possible to do some power management under
> Linux if ACPI or APM is not ported to mips ? And if yes, what would be
> the work to do ?
> 
> Thanks in advance,
> 
> Ivan
> 
> 

RE: power management on mips

[Mitchell, Earl]

APM is dead replaced by ACPI which is primarily used for x86 laptops 
I think. While back I read that MontaVista and IBM were working on 
something called Dynamic Power Mgmt (DPM). Might want to check that out? 
See links below. 

-earlm
 
http://www.linuxdevices.com/news/NS4297534594.html
http://tree.celinuxforum.org/CelfPubWiki/PowerManagementDefinitionOfTerms_5fR2
 


> -----Original Message-----
> From: linux-mips-bounce@linux-mips.org
> [mailto:linux-mips-bounce@linux-mips.org]On Behalf Of Ivan Korzakow
> Sent: Tuesday, October 18, 2005 9:01 AM
> To: linux-mips@linux-mips.org
> Subject: power management on mips
> 
> 
> Hi list,
> 
> Does anyone knows what power management features are there for mips ?
> I know for example that ACPI have been porting to arm. Anything
> equivalent for mips ? Is it possible to do some power management under
> Linux if ACPI or APM is not ported to mips ? And if yes, what would be
> the work to do ?
> 
> Thanks in advance,
> 
> Ivan
> 
> 

RE: power management on mips

[Peter Popov]

> I think. While back I read that MontaVista and IBM
> were working on 
> something called Dynamic Power Mgmt (DPM). Might
> want to check that out? 
> See links below. 

That's alive and well in shipping mobile phones and
perhaps other devices. However, it requires quite a
bit of work to port it to a new architecture/cpu and 
as far as I know it never went mainstream. You'll end
up with somewhat of a custom PM solution. Nothing
wrong with that, as long as you're willing to maintain
it internally as your kernel revs forward.

Pete
 
> -earlm
>  
> http://www.linuxdevices.com/news/NS4297534594.html
>
http://tree.celinuxforum.org/CelfPubWiki/PowerManagementDefinitionOfTerms_5fR2
>  
> 
> 
> > -----Original Message-----
> > From: linux-mips-bounce@linux-mips.org
> > [mailto:linux-mips-bounce@linux-mips.org]On Behalf
> Of Ivan Korzakow
> > Sent: Tuesday, October 18, 2005 9:01 AM
> > To: linux-mips@linux-mips.org
> > Subject: power management on mips
> > 
> > 
> > Hi list,
> > 
> > Does anyone knows what power management features
> are there for mips ?
> > I know for example that ACPI have been porting to
> arm. Anything
> > equivalent for mips ? Is it possible to do some
> power management under
> > Linux if ACPI or APM is not ported to mips ? And
> if yes, what would be
> > the work to do ?
> > 
> > Thanks in advance,
> > 
> > Ivan
> > 
> > 
> 
> 

RE: power management on mips

[Mitchell, Earl]

True. PDAs and mobile devices also use it. 
So it may be supported for platforms like
AMD's Alchemy (e.g. they have a PDA reference design).

-earlm

> -----Original Message-----
> From: linux-mips-bounce@linux-mips.org
> [mailto:linux-mips-bounce@linux-mips.org]On Behalf Of Peter Popov
> Sent: Tuesday, October 18, 2005 10:53 AM
> To: Mitchell, Earl; Ivan Korzakow; linux-mips@linux-mips.org
> Subject: RE: power management on mips
> 
> 
> 
> 
> 
> > I think. While back I read that MontaVista and IBM
> > were working on 
> > something called Dynamic Power Mgmt (DPM). Might
> > want to check that out? 
> > See links below. 
> 
> That's alive and well in shipping mobile phones and
> perhaps other devices. However, it requires quite a
> bit of work to port it to a new architecture/cpu and 
> as far as I know it never went mainstream. You'll end
> up with somewhat of a custom PM solution. Nothing
> wrong with that, as long as you're willing to maintain
> it internally as your kernel revs forward.
> 
> Pete
>  
> > -earlm
> >  
> > http://www.linuxdevices.com/news/NS4297534594.html
> >
> http://tree.celinuxforum.org/CelfPubWiki/PowerManagementDefini
tionOfTerms_5fR2
>  
> 
> 
> > -----Original Message-----
> > From: linux-mips-bounce@linux-mips.org
> > [mailto:linux-mips-bounce@linux-mips.org]On Behalf
> Of Ivan Korzakow
> > Sent: Tuesday, October 18, 2005 9:01 AM
> > To: linux-mips@linux-mips.org
> > Subject: power management on mips
> > 
> > 
> > Hi list,
> > 
> > Does anyone knows what power management features
> are there for mips ?
> > I know for example that ACPI have been porting to
> arm. Anything
> > equivalent for mips ? Is it possible to do some
> power management under
> > Linux if ACPI or APM is not ported to mips ? And
> if yes, what would be
> > the work to do ?
> > 
> > Thanks in advance,
> > 
> > Ivan
> > 
> > 
> 
> 

RE: power management on mips

[Mitchell, Earl]

True. PDAs and mobile devices also use it. 
So it may be supported for platforms like
AMD's Alchemy (e.g. they have a PDA reference design).

-earlm

> -----Original Message-----
> From: linux-mips-bounce@linux-mips.org
> [mailto:linux-mips-bounce@linux-mips.org]On Behalf Of Peter Popov
> Sent: Tuesday, October 18, 2005 10:53 AM
> To: Mitchell, Earl; Ivan Korzakow; linux-mips@linux-mips.org
> Subject: RE: power management on mips
> 
> 
> 
> 
> 
> > I think. While back I read that MontaVista and IBM
> > were working on 
> > something called Dynamic Power Mgmt (DPM). Might
> > want to check that out? 
> > See links below. 
> 
> That's alive and well in shipping mobile phones and
> perhaps other devices. However, it requires quite a
> bit of work to port it to a new architecture/cpu and 
> as far as I know it never went mainstream. You'll end
> up with somewhat of a custom PM solution. Nothing
> wrong with that, as long as you're willing to maintain
> it internally as your kernel revs forward.
> 
> Pete
>  
> > -earlm
> >  
> > http://www.linuxdevices.com/news/NS4297534594.html
> >
> http://tree.celinuxforum.org/CelfPubWiki/PowerManagementDefini
tionOfTerms_5fR2
>  
> 
> 
> > -----Original Message-----
> > From: linux-mips-bounce@linux-mips.org
> > [mailto:linux-mips-bounce@linux-mips.org]On Behalf
> Of Ivan Korzakow
> > Sent: Tuesday, October 18, 2005 9:01 AM
> > To: linux-mips@linux-mips.org
> > Subject: power management on mips
> > 
> > 
> > Hi list,
> > 
> > Does anyone knows what power management features
> are there for mips ?
> > I know for example that ACPI have been porting to
> arm. Anything
> > equivalent for mips ? Is it possible to do some
> power management under
> > Linux if ACPI or APM is not ported to mips ? And
> if yes, what would be
> > the work to do ?
> > 
> > Thanks in advance,
> > 
> > Ivan
> > 
> > 
> 
> 

RE: power management on mips

[Peter Popov]

--- "Mitchell, Earl" <earlm@mips.com> wrote:

> 
> True. PDAs and mobile devices also use it. 
> So it may be supported for platforms like
> AMD's Alchemy (e.g. they have a PDA reference
> design).


Yes, although I don't think AMD recommends switching
frequencies anymore. I think they rate/test the chip
only at its advertised speed. So static power
management could be implemented but Dynamic Power
Management (where most of the complexity is anyway)
would probably not be recommended by the manufacturer.

Pete

Re: power management on mips

[Daniel Jacobowitz]

On Tue, Oct 18, 2005 at 06:00:40PM +0200, Ivan Korzakow wrote:
> I know for example that ACPI have been porting to arm.

As far as I know, that's not true.

-- 
Daniel Jacobowitz
CodeSourcery, LLC