Re: PXA27x UDC Power
David Brownell <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
On Wednesday 28 November 2007, Justin Clacherty wrote: > David Brownell wrote: > > Right now the only way to do that is to modify your configuration > > descriptors. > > > I expected that would be the case but I didn't like the idea of putting > machine specific configurations in ether.c. Is this a problem with the > gadget subsystem in general or just the PXA? I'm not sure I see it as a problem. At that level, power management is highly product-specific -- if you want anything other than very generic behavior. Part of the reason you want source code is specifically so you can customize stuff like that. Plus, didn't you say you wanted multiple configurations ... a standard one, and a higher power one for battery recharging? > I've seen that there is a call to vbus_draw once the device is > configured and I can change the current draw to 500mA here but how will > I know if the device I'm attached to can supply the required 500mA? You get connected to a host ... the host chooses a configuration it can support. The ability to supply 500mA is an attribute of the port the gadget is hooked up to. For example, unpowered hubs provide only 100 mA per port, but most powered ones can supply 500mA (or even more). - Dave ------------------------------------------------------------------------- SF.Net email is sponsored by: The Future of Linux Business White Paper from Novell. From the desktop to the data center, Linux is going mainstream. Let it simplify your IT future. http://altfarm.mediaplex.com/ad/ck/8857-50307-18918-4 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel