On Mon, Dec 17, 2001 at 07:51:49PM +0000, Riley Williams wrote:
>
> Keeping that in mind, let's take some scenarios that are already here
> and need to be dealt with by the USB subsystem:
>
> 1. Simon's laptop has no keyboard on the body of the laptop,
> and is supplied with a separate one with a USB connector
> with which Simon plugs it into one of the four USB ports
> on the laptop's body. Simon also has a USB modem which he
> takes with him and plugs in whenever he needs it, and a
> USB barcode reader that is used regularly. The port each
> gets connected to is determined mainly by the order he
> plugs them in before pressing the resume button.
>
> 2. Philip's laptop normally runs with a USB Zip-250 drive to
> prepare and update databases for his customers, with his
> customer base being spread around Europe. When he packs
> it up for transport from one customer to another, he needs
> to comply with the requirements of the airline he is flying
> with, so the drive gets unplugged between customers.
>
> Simon and Philip are both friends of mine, and the systems referred to
> actually exist. Both are currently using Win2K based systems, and they
> have no problems using the SUSP/RESM button between sessions, and never
> worry about which port they plug the various USB items into. As Simon
> put it recently, "With Windows 2000, they just work".
>
> Basically, how does the current Linux USB subsystem handle those two
> scenarios? The descriptions I've seen on this list basically claim that
> it doesn't handle them at all, and if so, it's seriously faulty and
> needs to be dealt with.
Ok, in order of devices, how Linux handles them:
- USB keyboard:
- on Linux, works in any port, so a suspend and resume will work
just fine.
- USB modem:
- Simon only has 1 modem, so no matter where he plugges it in on
the USB topology, it will always be referenced as the same
modem: /dev/ttyACM0
- USB Barcode reader:
- Most all barcode readers look like a USB keyboard to the host.
So again, all keyboards are multiplexed together, and everything
will work just fine.
- If the barcode reader is a HID device, the HID userspace
interface will talk to the device just fine, no matter where on
the toplogy it is.
- USB Zip drive:
- Usually zip drives have a serial number per media device (is
this correct Matt?) Either way, it is the only USB mass storage
device in the system, so it always is mounted at the same place.
Did that help?
thanks,
greg k-h
_______________________________________________
[EMAIL PROTECTED]
To unsubscribe, use the last form field at:
https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
