Re: X: SampleUSBMIDIDriver / SetConfiguration question

Subject: Re: X: SampleUSBMIDIDriver / SetConfiguration question
From: Barry Twycross <email@hidden>
Date: Fri, 20 Sep 2002 10:40:18 -0700

At 3:52 PM +0200 9/20/02, Laurent Humbert wrote:

There has been an upgrade in the device's hardware/firmware, and now the USBDevice::OpenAndConfigure fails because the call to SetConfiguration returns "device not responding".

My question: Is there anything I can do to work around the problem or do I tell the manufacturer that it's really their fault and that the device *must* respond to SetConfiguration calls immediately after USBDeviceOpen, even when it's just been switched on ?

What you really need is a bus trace. Once you know what's going on on the bus, then you have a case for complaining to the manufacturer.

A device must indeed respond to a SET_CONFIGURATION at any time it is legal* to send such a command. Without a bus trace you don't exactly know what's going on.

* Accroding to the spec SET_CONFIGUATION is legal in any state except the default state. That is the device must have had its address set first (with a SET_ADDRESS command). Also a device is allowed 3ms to recover from a SET_ADDRESS before it must respond to a command. -- Barry Twycross email@hidden --- USB, it's not a Dyslexic BUS. (Thanks to TC.) _______________________________________________ usb mailing list | email@hidden Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/usb Do not post admin requests to the list. They will be ignored.

References:
	>X: SampleUSBMIDIDriver / SetConfiguration question (From: Laurent Humbert <email@hidden>)

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