Am Freitag 09 April 2010 21:04:19 schrieb Alan Stern: > On Fri, 9 Apr 2010, Hendrik Sattler wrote: > > Am Freitag 09 April 2010 16:52:12 schrieb Alan Stern: > > > On Fri, 9 Apr 2010, Hendrik Sattler wrote: > > > > I found some additional problems with f_obex: > > > > 1. > > > > After the client disconnects, a select() call with one FD checking > > > > for input data wil always return immediately but read() return 0. I > > > > fixed this by closing the device and re-opening. tcflush() doesn't > > > > help. > > > > > > Why is that a problem? Isn't it supposed to work that way? > > > > I certainly didn't expect it on the gadget (server) side, normal on the > > host (client) side. > > Serial connections are symmetrical, so the same behavior should pertain > to both ends of the connection, right? > > > There's already SIGHUP when the cable is disconnected which is only > > useful to reset the internal state of the obex application. I have not so > > much knowledge about USB but on the server application side, it's a > > sudden strange behaviour of select(), as it signals that there is data to > > read when there's none. > > Actually it signals that a read will return immediately, as opposed to > blocking. So it isn't sudden strange behavior. Ok, I get your point. Can the complete behaviour of ttyGS* be documented under Documentation/usb/? There were quite some points that I either had to look up in kernel source, or the behaviour above. > > BTW: Is there a way to have enough endpoints to that "modprobe g_serial > > use_acm=1 use_obex=1" produces a result that makes ACM and OBEX > > available? Currently, I can choose one or the other, not both. > > Dummy-hcd is flexible; you can get any number of endpoints you want (up > to the maximum), with various restrictions on their use, just by > editing the ep_name[] array near the start of the source file. For > example, you could add ep-g, ep-h, ..., ep-z and remove all the > numbered endpoints; that would give you 26 configurable endpoints. I > trust that would be enough. :-) How can I tell from userspace if /dev/ttyGS* is for ACM or OBEX (or anything else that comes along later)? HS -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
