On 6 Feb, 2014, at 11:16 , Matthias Drochner <m.droch...@fz-juelich.de> wrote: > On Thu, 6 Feb 2014 19:50:04 +0100 > Marc Balmer <m...@msys.ch> wrote: >> If I find the spot, I will probably remove it. > > It is line 784 in dev/ic/com.c. It depends on the HUPCL > flag unset which is done around line 1344, depending > on SOFTCAR. > The comment in com_shutdown() makes some sense, but > it could be done more elegantly, eg set a timer and > do the delay on next open if it is done immediately.
I think the logic is broken in any case, it shouldn't be doing this in com_shutdown(). Notice that com_shutdown() isn't always executed on last close (which is when the documentation says the HUPCL flag is supposed to have an effect), it is executed on last close only when no one is waiting for open, e.g. waiting for the dial-in device to go active. Yet the case where someone is waiting for the dial-in device is exactly the situation where you want to make sure the previous phone call is hung up, so the dial-in guy doesn't end up talking to the call the dial-out guy made. com_shutdown() shuts down the hardware. You only want to shut down the hardware when no one has the device open and no one is waiting for it to be open (i.e. the condition under which it is called is correct), but if HUPCL is set you want to drop DTR on last close whether anyone is waiting or not. I hence think the delay needs to be removed from com_shutdown() in any case, and moved somewhere else, for this to work correctly. If you just removed the delay from com_shutdown() and didn't move it somewhere else, however, it might be that no one would ever notice... Dennis Ferguson
