iPod Nano

[Lennart Sorensen]

On Tue, Oct 23, 2007 at 04:32:34PM -0400, Chris Aitken wrote:
> Do I assume that my USB port is /not/ 2.0?

On a P3, yes that would be a good assumption.  Some P4s had a mix of
USB1 and 2 ports (SIS chipsets were notorious for doing that).  I don't
think I ever saw a P3 with USB2 ports built in.

One way to check is run lsmod|grep ehci.  ehci is the driver for usb2
ports, while usb1 ports use only uhci or ohci driver (depending on who
made it).

You can also tell from 'lspci'.  For example here is the output on a VIA
KT800Pro based board:

00:10.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
00:10.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
00:10.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
00:10.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 81)
00:10.4 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 86)

It has USB 2.0, and uses UHCI for USB 1 compatibility.  USB uses dual
controller for USB2 ports, since that way USB1 devices can talk to a
USB1 controller, while USB2 devices can talk to the USB2 controller.  It
also means if the OS doesn't have drivers for USB2 (EHCI) but does have
USB1 drivers, you can still run everything, but all the USB2 devices
drop down to USB1 speeds for compatibility with the old OS.

The above list means the system has 4 USB root controllers (4 UHCI
controllers in this case), each of which has 2 ports (root controllers
tend to have 2 ports each), and then it has a USB2 controller on top of
that to provide USB2 services to those 4 root controllers.

Similar output on an i865 chipset system:
00:1d.0 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #3 (rev 02)
00:1d.3 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB UHCI Controller #4 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801EB/ER (ICH5/ICH5R) USB2 EHCI Controller (rev 02)

Same layout of ports as the other system.

An older system I have looks like this (VIA KT133 chipset):
00:04.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 10)
00:04.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 10)

Just 2 USB1 controllers on it (4 ports total).

My mythtv box (Nvidia nforce2 chipset):
00:02.0 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)
00:02.1 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)
00:02.2 USB Controller: nVidia Corporation nForce2 USB Controller (rev a4)

This one is actually less useful, given it doesn't tell you anything.
It is actually 3 usb controllers (so 6 ports) and it does do USB2,
although it does not present a seperate PCI device for that.  ehci
driver is loaded on it though.  lspci -vv does however show them as OHCI
and EHCI USB controllers.

--
Len Sorensen
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