Hi folks, this series resolves an issue for hvc back-ends that transfer terminal data over an established communication path. The current implementation of the hvc_console layer notifies its back-ends for tty open, close, and hangups. However, there are conditions where the hangup-on-close (HUPCL) termios flag must be considered, for example, when doing a vhangup(). For the hvc_iucv back-end, users perceives disconnects at their login which are triggered by a modified vhangup() invocation as described in https://lkml.org/lkml/2012/6/5/145. (The kernel change implied also a change in the login program). However, this also necessitates to inform back-ends about changes in the DTR/RTS control lines which actually depend on the setting of the HUPCL termios flag. Like in the old days for modems, network-based back-ends need to know when to hang-up and drop off an established communication path. Without this new notification, back-ends can only use the tty open, close, hangup notifiers to decide whether to disconnect. This is not sufficient because the HUPCL flag can be cleared (i.e. not to hang-up a connection) when last tty file descriptor is closed. This series adds the dtr_rts() callback to the hvc_console layer and modifies the hvc_iucv device driver to disconnect an established IUCV connection only when the DTR/RTS is lowered. Feedback is very welcome. Thanks in advance! Kind regards, Hendrik -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
