Messages in this thread |  | | | Date | Sun, 24 Sep 2006 22:20:25 +0200 | | From | Pavel Machek <> | | Subject | Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1 |
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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 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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