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

From: David Brownell
Date: Wed Sep 27 2006 - 19:05:51 EST

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.

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