On Thu, 6 Aug 2015, Laszlo Papp wrote: > Hi Alan, > > On Wed, Aug 5, 2015 at 7:15 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > On Wed, 5 Aug 2015, Greg KH wrote: > > > >> hm, wait, is this really the n_gsm line discipline? Or is it something > >> else? > >> > >> g_serial is the device side of a serial connection, there is no "cable > >> removed" notification that it even knows about, that has to come from > >> the gadget driver somehow, which you should listen for and then kick > >> your userspace program. > > > > There is the gserial_disconnect() callback, which gets invoked when the > > Vbus power (provided by the host) is removed. It's a pretty good > > indicator that the USB cable has been unplugged. > > > > I don't understand all the stuff that gserial_disconnect() does, but it > > ought to be more or less equivalent to a "hangup" -- as the kerneldoc > > says. If it doesn't do what users expect, there's probably a bug > > somewhere. > > > > Of course, it's possible that the callback does not get invoked in > > Laszlo's case. Then the question would be: Why not? > > Hmm, that is a good question. I wonder if there had been any recent > fixes for that lately... I suppose that I will need to skim through > the git log. Thank you for the hints! You should also add a printk statement to the disconnect callback so that you can verify whether it really is getting called. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
