On Tue, 6 Mar 2007, Valentin Longchamp wrote:

> Alan Stern wrote:
> > > c->desc.bMaxPower is what the hub makes available for each port and
> > > udev->bus_mA is what the device requests.
> >
> > It's the reverse: (c->desc.bMaxPower * 2) is what the device requests and
> > udev->bus_mA is what the hub makes available.
> 
> Ok. So the hub code rejects a device needing 150 mA (which resluts in 300) 
> althoug the MIC2536 is able to provide 150 mA. For me it rejects a 
> configuration that should be accepted, doestn't it ?

No, no.  If c->desc.bMaxPower == 150 then the device really needs 300 mA.  
Remember, the value in the descriptor is given in units of 2 mA.  (That's 
how it manages to pack values ranging up to 500 in a single byte.)  So the 
driver is rejecting a configuration which should be rejected.

Alan Stern


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