Diagnosing a USB problem (OT, Long, Boring)

[Bill]

I think I need a real expert on usb to help look at a problem before my trial copy of Windows 7 64-bit expires. I've asked all over the place and have made some progress, but......

The basic problem is a weird situation under that OS with a couple of different usb 1.1 audio interfaces (Edirol and M-Audio). I suspect that many of the problems reported by others with similar setups may be related to this.

I have a cheap but reasonable Acer laptop with AMD RM-74 processor and

4GB. All drivers are up to date and hardly anything can be bodged in the bios.

If I plug one of the audio interfaces into the machine directly and use asio drivers, audio is unusable unless I open Windows Control Panel, select Sounds and go to the Recording tab. Then it records and plays fine. Disabling the on-board audio completely also makes it unusable. If I enable and use the wdm drivers of the usb interface, it works OK. With the i.f into the machine directly, it shows the device connected at "Full Speed" ie usb 1.1 in device manager. If I run the machine with the usb i/f connected through a usb 2 hub it works fine and the hub shows connected at "High Speed" and the i/f connected to it at "Full speed". So the external hub alters the usb routing inside the PC as expected. The obsolete USBView program runs on the machine, the replacement USB20CV gives a "Could not select Test Stack" error which doesn't respond to the cures shown on the Release Notes. USB20CV runs fine on a Vista 32 machine, and these interfaces work perfectly when I put Vista

32 back into the test machine.

I suspect that this is a routing problem between the usb bits of the chipset in the mainboard. Acer have Win7 64-bit drivers for the machine, but no specific main chipset drivers.

Any ideas about how to understand what the real problem is would be very welcome.

[Peter Crosland]

There are differences between the USB 1.1 and USB 2.0 protocols. Just a guess but this could be the problem. There is quite a detailed article here.

might find more expertise in one of the specialised computing NGs.

Peter Crosland

[newshound]

Might try uk.comp.homebuilt....

[Bill]

In message , newshound writes

Have now posted there. I have, though tried 4 specialist Microsoft forums, a usb forum and the M-Audio forum in the recent past. Getting anyone to understand the question is the main problem. I really ought to join a forum about clear writing!

[Richard Skeen]

Some random thoughts, rather than an answer...

The USB host controller on the PC normally presents both a legacy interface (UCHI or OHCI) for low-speed and full-speed devices and a USB

2.0 EHCI interface for talking to full speed devices.

If you plug a full-speed device in via an external high-speed hub, the PC will talk to it via the EHCI interface via the "transaction translator" in the external hub, if connected directly it will go via the UHCI/OHCI controller. You should be able to see this if you open Device Manager (start->run->devmgmt.msc or via 'system' in Control Panel) and select "view devices by connection".

Does Device Manager show any errors?

Does a USB mouse/keyboard (which is a low speed device) work correctly if plugged directly into the machine?

So there sounds like there's something fishy with the UHCI/OHCI driver for your host controller under 64-bit windows, but or more specifically with isochronous support if a keyboard/mouse works but an audio device doesn't. However, I can't see how opening the control panel settings would magically make the audio work when it didn't otherwise.

Richard.

[Bill]

In message , Richard Skeen writes

Yes, and when plugged in directly, the audio interface appears on a "OpenHCD" connected USB Root Hub. When I plug in the external hub, this hub connects via one of the 2 "Standard Enhanced PCI to USB" connected root hubs.

Yes. It all looks fine

No, no errors

A USB Wireless Keyboard/mouse connects through an OHCI Channel and works correctly. It works fine on one channel while the audio interface is bad on another channel.

Exactly, and it is just that one tab in the Sounds panel which relates to the wdm audio drivers, not the asio ones that are in use.