Re: [linux-usb-devel] USB devices fail unnecessarily on unpowered hubs

[Oliver Neukum]

Am Montag, 5. Juni 2006 16:32 schrieb David Brownell:
> On Saturday 03 June 2006 2:29 am, Oliver Neukum wrote:

> > If that does the job we need to somehow inherit the power supply maximum from
> > PCI when we allocate the root hub's device structure.
> 
> I don't think there is such a convention that's generic for PCI.  There might
> be ACPI-specific tables holding that value, but on embedded hardware the model
> is often that the arch/.../board-ZZZ.c file just "knows" things like how much
> power the regulator powering that port can provide, and arranges bus_mA to match.
> Just like it knows all sorts of other details about how that board works.

Yes, I am afraid it cannot be done on the fly. But we might use a symbolic
define which a subarch can override instead of a literal "500".
If it turns out that this problem is one of power and not some other
deficiency of this system's root hub.

	Regards
		Oliver
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