Enumeration shows USB Stick as part hub part bulk storage?

[davepaxton]

Hi,
I have tried several USB Sticks with mostly positive results but this one has me stumped.
After insertion in one of the two ports of the root hub of controller 0, (the other root hub port is vacant)
"USBUHCI addressdata" gives the following output which seems to show the "Prolific Technology Inc" device as part hub, part bulk storage.

Just for information, the device happens to be a bootable USB stick formatted fat32
and happens to hold a copy of the FREEDOS operating system on it!
If I load USBDRIVE I can access a single drive letter F: to successfully read the content.


Can anyone explain what is happening here?
Output follows (apologies for some poor formatting!)
Regards
Dave Paxton

USBUHCI 0.14, (C) 2007-2010, Bret E. Johnson.
DOS Driver for a Universal HCI compatible USB Host Controller.


DEVICE ADDRESSES
═══════════════════════════════════════════════════════════════════════════════
Host Index: 0 Host Type: UHCI Bus Type: PCI IRQ#: 9 Root Hub Ports: 2
Vendor: 1106h = VIA Technologies Inc Product: 3038h
═══════════════════════════════════════════════════════════════════════════════
DEVICES INTERFACES
═════════════════════════════════════════════ ════════════════════════════════
L C I A O
ADRS o P o n l w
════ (hex) S o BUS n t t n
Test VEND PROD Sub Pro p USB HUB r POWR f f I e Sub Pro
RWak ID ID Cls Cls col d VER ADR t (mA) g c n DESCRIPTION d Cls Cls col
════ ════ ════ ═══ ═══ ═══ ═ ═══ ═══ ═ ════ ═ ═ ═ ══════════════ ═ ═══ ═══ ═══
1 1106 3038 9 0 0 . 1.0 ... . s 0 1 0 0*Root Hub Y 9 0 0
VIA Technologies Inc
──── ──── ──── ─── ─── ─── ─ ─── ─── ─ ──── ─ ─ ─ ────────────── ─ ─── ─── ───
2 067B 2515 9 0 0 . 2.0 1 2 s100 1 0 0*Hub v1 Generic Y 9 0 0`
Prolific Technology Inc
──── ──── ──── ─── ─── ─── ─ ─── ─── ─ ──── ─ ─ ─ ────────────── ─ ─── ─── ───
3 067B 2517 0 0 0 . 2.0 2 1 s 2 1 0 0*SFF-8070i Bulk . 8 5 80
Prolific Technology Inc

[Bret]

In addition to USBUHCOI, you must also have USBHUB loaded? If not, you would see the hub but not the mass storage.

Anyway, I've never seen a mass storage device that had a "fake" hub like this, though I must say I'm not completely surprised. Manufacturers sometimes do very strange things with the devices. It's possible that the chip set used in your flash drive can actually handle two separate disks internally (like a disk and a CD-ROM), but for some reason they disabled the second port of the hub. From my limited exposure, Prolific seems to be known more for serial / modem / communications type devices than mass storage, so maybe the second port can be configured as some kind of communications device. Just some guesses.

The only kind of device I've personally seen with a built-in hub like this was a keyboard that had an extra USB port on the side of it, presumably to plug in a mouse. The keyboard was set up in the software as a hub with two ports, with the keyboard attached (permanently) to one of the ports and the other port normally empty.

I'm also right now using a USB keyboard that has a PS2 port on the side of it, that you can use to plug in a PS2 mouse which gets emulated as a USB mouse via the keyboard. I don't actually use that feature, but use a "real" USB mouse instead.

Also, for formatting text like this in the forum, you can treat it as source code (select the "Code" button from the menu).

[davepaxton]

Bret,
Thanks for the feedback on this.
You were quite correct with the statement about "you must have USBHUB installed ....." although I had not spotted that!
With no USBHUB installed USBUHCI /addressdata only picks up the "HUB" part of the device which I guess is at least
consistent with what we would anticipate in seeing.

As a storage device it seems to work ok which is more than I have found with other USB sticks!.
I will if I may post other queries concerning some of these other devices.
As you say in a summary part of your documentation "USB is EXTREMELY complicated and confusing ...."!!!!!

Thanks for tip about "Code" submission
Regards
Dave