On Mon, Dec 17, 2001 at 07:30:32PM +0000, Riley Williams wrote: > > That deferring may not always be possible. As an example, take a system > in use by a friend of mine, basically a laptop with the keyboard not > part of the main unit, but on the end of a USB lead that has to be > disconnected to get it in its carrycase - and it has FOUR USB ports on > the main case. As it happens, Simon uses it exclusively under Win2K, and > that doesn't care what port the keyboard is plugged into on resume. If > he chose to run it under Linux, would that care?
Both Linux and Windows multiplex all keyboards together (USB and ps2), so no, Linux does not care about where on the USB tree it exists. > Remember, one of the basic design aims of USB was that the location a > device is plugged in is irrelevant to the user. Heh, that might have been a nice goal at the beginning of the USB spec process, but then reality hit :) USB printer drivers on Windows for some manufacturers use the device serial number to keep track of where the user plugged in a specific printer, to keep that printer's settings correct. Lots of printers do not have serial numbers, so those driver authors have to use the topology. USB to serial drivers on Windows also do this same thing (mostly they rely on the usb topology). And in talking with some of the core USB spec authors, they wish they had mandated the serial number option to help alleviate some of the problems that now happen. > The Linux USB drivers need to be totally transparent to where a > particular device is plugged in, otherwise they're essentially > useless. Not true at all. If a driver knows where a device is, it can do more things. Currently no Linux driver cares about topology, but that might change in 2.5. thanks, greg k-h _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
