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Changes between Initial Version and Version 1 of Ticket #96, comment 39

initial	v1
1	1	My system has 3 EHCI host controllers. I swapped my USB Audio 2.0 device between the first and the third EHCI host controller and there were no problems.
2	2
3		The class drivers (USBAUDIO, USBAUD2 but also USBMSD etc.) are agnostic to the specific host controller they are attached to other than the fact, that they get reported by USBD.SYS what host controller a device is attached to so that they can route the request to the correct host controller. That said, in reality, they instead route the request to USBD.SYS which then sets up the transfer using the correct host controller (the one it reported to the class driver earlier).
	3	The class drivers (USBAUDIO, USBAUD2 but also USBMSD etc.) are agnostic to the specific host controller they are attached to other than the fact, that they get reported by USBD.SYS what host controller a device is attached to (USBD.SYS detects new device insertions and therefore also knows to what host controller they have been attached to) so that they can route the request to the correct host controller. That said, in reality, they instead route the request to USBD.SYS which then sets up the transfer using the correct host controller (the one it reported to the class driver earlier).
4	4
5	5	I cannot see how the class drivers behaviour would lead to effects on host controllers the device is not even attached to. But maybe the trap screen (of USBAUD2.SYS) can give a clue of what is going wrong.