Hi Greg. >> 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. Good. > - 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 Good. > - 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. At work, I use a USB barcode reader that appears as a serial port to the software that uses it (I know coz I checked). How does that fit into this scheme of things? > - USB Zip drive: > - Usually zip drives have a serial number per media device (is > this correct Matt?) If so, that's no problem. > Either way, it is the only USB mass storage device in the > system, so it always is mounted at the same place. Good so far... However, what happens if Philip adds a USB CD-RW to his system - how does that affect things? Best wishes from Riley. _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
