usb still sucks battery in -rc7-mm1

usb still sucks battery in -rc7-mm1

[Pavel Machek]

Hi!

I made some quick experiments, and usb still eats 4W of battery
power. (With whole machine eating 9W, that's kind of a big deal)...

This particular machine has usb bluetooth, but it can be disabled by
firmware, and appears unplugged. (I did that). It also has fingerprint
scanner, that can't be disabled, but that does not have driver (only
driven by useland, and was unused in this experiment).

Any ideas?
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1

[Theodoros V. Kalamatianos]

On Sun, 24 Sep 2006, Pavel Machek wrote:

> I made some quick experiments, and usb still eats 4W of battery
> power. (With whole machine eating 9W, that's kind of a big deal)...
>
> This particular machine has usb bluetooth, but it can be disabled by
> firmware, and appears unplugged. (I did that). It also has fingerprint
> scanner, that can't be disabled, but that does not have driver (only
> driven by useland, and was unused in this experiment).
>
> Any ideas?

(I have not followed the thread, so bear with me if I say anything 
irrelavant)

I have encountered at least 3 hubs (2 usb2 & 1 usb1) that will consume a 
lot of power (about 2-2.5W if the laptop power consumption readings are to 
be trusted) and heat up a lot (to the point of being too hot to touch for 
more than a few seconds) even when no devices are connected, at least on 
Linux. I have not tested them on a Windows machine to see if this is the 
case there. The USB2 ones used Cypress chips. I do not know what your h/w 
config is, but perhaps this is a similar case ?


Regards,

Theodoros Kalamatianos


PS: Note that the 2-2.5W consumption is the maximum that the laptop USB 
port can provide, and I have noticed that with the hub's external power 
supply connected it heats up even more.

Re: usb still sucks battery in -rc7-mm1

[Alexander Gran]

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Perhaps your cpu cannot go into deep c states? At least my IBm T40p has that 
problem, when USB is enabled.

regards
Alex

Am Sonntag, 24. September 2006 11:08 schrieb Pavel Machek:
> Hi!
>
> I made some quick experiments, and usb still eats 4W of battery
> power. (With whole machine eating 9W, that's kind of a big deal)...
>
> This particular machine has usb bluetooth, but it can be disabled by
> firmware, and appears unplugged. (I did that). It also has fingerprint
> scanner, that can't be disabled, but that does not have driver (only
> driven by useland, and was unused in this experiment).
>
> Any ideas?
> 								Pavel

-- 
Encrypted Mails welcome.
PGP-Key at http://www.grans.eu/misc/pgpkey.asc | Key-ID: 0x6D7DD291
More info at http://www.grans.eu/Alexander_Gran.html

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: usb still sucks battery in -rc7-mm1

[Pavel Machek]

On Sun 24-09-06 16:49:59, Alexander Gran wrote:
> Perhaps your cpu cannot go into deep c states? At least my IBm T40p has that 
> problem, when USB is enabled.

Yes, and latest -mm's were expected to fix that...

							Pavel

> 
> regards
> Alex
> 
> Am Sonntag, 24. September 2006 11:08 schrieb Pavel Machek:
> > Hi!
> >
> > I made some quick experiments, and usb still eats 4W of battery
> > power. (With whole machine eating 9W, that's kind of a big deal)...
> >
> > This particular machine has usb bluetooth, but it can be disabled by
> > firmware, and appears unplugged. (I did that). It also has fingerprint
> > scanner, that can't be disabled, but that does not have driver (only
> > driven by useland, and was unused in this experiment).
> >
> > Any ideas?
> > 								Pavel
> 
> -- 
> Encrypted Mails welcome.
> PGP-Key at http://www.grans.eu/misc/pgpkey.asc | Key-ID: 0x6D7DD291
> More info at http://www.grans.eu/Alexander_Gran.html



-- 
Thanks for all the (sleeping) penguins.

Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1

[Pavel Machek]

Hi!

> >I made some quick experiments, and usb still eats 4W of battery
> >power. (With whole machine eating 9W, that's kind of a big deal)...
> >
> >This particular machine has usb bluetooth, but it can be disabled by
> >firmware, and appears unplugged. (I did that). It also has fingerprint
> >scanner, that can't be disabled, but that does not have driver (only
> >driven by useland, and was unused in this experiment).
> >
> >Any ideas?
> 
> (I have not followed the thread, so bear with me if I say anything 
> irrelavant)
> 
> I have encountered at least 3 hubs (2 usb2 & 1 usb1) that will consume a 
> lot of power (about 2-2.5W if the laptop power consumption readings are to 
> be trusted) and heat up a lot (to the point of being too hot to touch for 
> more than a few seconds) even when no devices are connected, at least on 
> Linux. I have not tested them on a Windows machine to see if this is the 
> case there. The USB2 ones used Cypress chips. I do not know what your h/w 
> config is, but perhaps this is a similar case ?

> PS: Note that the 2-2.5W consumption is the maximum that the laptop USB 
> port can provide, and I have noticed that with the hub's external power 
> supply connected it heats up even more.

I'm not using any external hubs. I believe it is old "uhci keeps cpu
from reaching deep c states" problem. I just want to ping greg/list,
because greg told me problem is solved in -mm.
								Pavel 
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1

[Alan Stern]

On Sun, 24 Sep 2006, Pavel Machek wrote:

> Hi!
> 
> I made some quick experiments, and usb still eats 4W of battery
> power. (With whole machine eating 9W, that's kind of a big deal)...
> 
> This particular machine has usb bluetooth, but it can be disabled by
> firmware, and appears unplugged. (I did that). It also has fingerprint
> scanner, that can't be disabled, but that does not have driver (only
> driven by useland, and was unused in this experiment).
> 
> Any ideas?

The USB autosuspend patches are still not entirely in -mm.  They contain a
couple of bugs that have to get fixed first.  When they do get merged you
should see considerable improvement.  Note that although they will reduce
the amount of power being used by the USB controllers and will stop the
DMA activity (thus allowing your CPU to enter C2), they won't put the
controllers into D3.  For that you'll have to get PCI autosuspend...  :-)

In the meantime, if all you care about is power consumption there are 
some things you can do.  The easiest is simply to rmmod ehci-hcd, 
ohci-hcd, and uhci-hcd.  After all, if you're not using USB there's no 
reason to let the drivers eat up memory, CPU time, and power.

Alan Stern

Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1

[Pavel Machek]

Hi!

> > I made some quick experiments, and usb still eats 4W of battery
> > power. (With whole machine eating 9W, that's kind of a big deal)...
> > 
> > This particular machine has usb bluetooth, but it can be disabled by
> > firmware, and appears unplugged. (I did that). It also has fingerprint
> > scanner, that can't be disabled, but that does not have driver (only
> > driven by useland, and was unused in this experiment).
> > 
> > Any ideas?
> 
> The USB autosuspend patches are still not entirely in -mm.  They contain a
> couple of bugs that have to get fixed first.  When they do get merged you
> should see considerable improvement.  Note that although they will reduce
> the amount of power being used by the USB controllers and will stop the
> DMA activity (thus allowing your CPU to enter C2), they won't put the
> controllers into D3.  For that you'll have to get PCI autosuspend...
> :-)

I have not measured that, but I _hope_ drain by controller itself will
not be big enough.

> In the meantime, if all you care about is power consumption there are 
> some things you can do.  The easiest is simply to rmmod ehci-hcd, 
> ohci-hcd, and uhci-hcd.  After all, if you're not using USB there's no 
> reason to let the drivers eat up memory, CPU time, and power.

Are autosuspend patches available somewhere? (Relative to -mm, or
relative to 2.6.18?) I'd like to play with them...
								Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1

[Alan Stern]

On Sun, 24 Sep 2006, Pavel Machek wrote:

> Are autosuspend patches available somewhere? (Relative to -mm, or
> relative to 2.6.18?) I'd like to play with them...

The versions in the mailing list archives are a little old.  I'll post
some updates later this week.

Alan Stern

Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1

[David Brownell]

On Sunday 24 September 2006 5:18 am, Theodoros V. Kalamatianos wrote:

> I have encountered at least 3 hubs (2 usb2 & 1 usb1) that will consume a 
> lot of power (about 2-2.5W if the laptop power consumption readings are to 
> be trusted) and heat up a lot (to the point of being too hot to touch for 
> more than a few seconds) even when no devices are connected, at least on 
> Linux. I have not tested them on a Windows machine to see if this is the 
> case there. The USB2 ones used Cypress chips. I do not know what your h/w 
> config is, but perhaps this is a similar case ?

Probably not unrelated.  I have one of those Cypress-based hubs; it's nice
except for the heat/power, which precludes using them in bus-powered mode
with a laptop (or anything) ... I don't much like wall-warts!

It might be too much to expect that when that hub's upstream port is
suspended, its power usage goes to something reasonable.