Hello. On Fri, 2008-02-22 at 03:06, Andy Green wrote: > > But every USB host I ever saw has current limit and high-side switch. > So I don't expect to find these kind of hosts,
Well, then let me tell you a story that this is not so unproblematic as you may think. Some time ago I had problems with the onboard graphics card of my current notebook, T40p so not really and old or cheap one. The first thing, before anything else, the technican that arrived at my place to replace the board, asked me was "What kind of USB devices did you attach to this notebook?" So we had a nice technical chat about the proeblems he see in his day-by-day work about UЅB devices drawing to much power from the controller. He explains that there are tons of cheap USB devices out there that don't care about the spec. Sometimes only the controller was broken, sometimes the whole board. Of course there are ways to avoid such problems in hw on the controller side. But what if the vendor liked to save one cent or had this pragmatic approach that nothing bad will happen and the time pressure got higher and higher... ;) regards Stefan Schmidt
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