Hi, On Mon, Aug 07, 2017 at 11:18:44PM +0200, Samuel Thibault wrote: > > static void spk_ttyio_send_xchar(char ch) > > { > > + if (check_tty(speakup_tty)) > > + return; > > + > > speakup_tty->ops->send_xchar(speakup_tty, ch); > > } > > This is still unsafe: the unplug might come just between testing for > speakup_tty becoming NULL and using it. I thought about that but couldn't find a way to overcome it in a foolproof way. Here's my reasoning. Since the unplugging of usb is asynchronous to us calling methods on speakup_tty, speakup_tty can become null in a separate thread. In situation where usb is unplugged immediately before we call a method on speakup_tty, even if we deactivate speakup the method on null speakup_tty will still be called. Have I missed something? Thanks, Okash _______________________________________________ Speakup mailing list Speakup@xxxxxxxxxxxxxxxxx http://linux-speakup.org/cgi-bin/mailman/listinfo/speakup