From owner-freebsd-hackers Thu May 27 0:54: 6 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from zed.ludd.luth.se (zed.ludd.luth.se [130.240.16.33]) by hub.freebsd.org (Postfix) with ESMTP id 40BD615869 for ; Thu, 27 May 1999 00:53:59 -0700 (PDT) (envelope-from pb@ludd.luth.se) Received: from father.ludd.luth.se (pb@father.ludd.luth.se [130.240.16.18]) by zed.ludd.luth.se (8.8.5/8.8.5) with ESMTP id JAA07035 for ; Thu, 27 May 1999 09:53:58 +0200 From: Peter Brevik Received: (pb@localhost) by father.ludd.luth.se (8.6.11/8.6.11) id JAA00777 for freebsd-hackers@freebsd.org; Thu, 27 May 1999 09:53:57 +0200 Message-Id: <199905270753.JAA00777@father.ludd.luth.se> Subject: RS232 status lines, read with TIOCMGET.. [solved] :) To: freebsd-hackers@freebsd.org Date: Thu, 27 May 1999 09:53:56 +0200 (MET DST) X-Mailer: ELM [version 2.4ME+ PL15 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Some of you maybe saw my letter about the (4)tty ioctl "TIOCMGET int *state". The issue has been solved and the answer is that indeed the sio.c driver only reads the status line at opening. However a status line change will trigger a interrupt, and cause the driver to read status lines once more. Thus functionality achived with minimum cpu load. Seems the status lines are not sensitive for ground connection. Ie it will not change bit value between gnd connection and no connection. I guess that was a bad TTL habit :-) Maybe this could be used in freebsd handbook or other documentation.. ? (to help others) /Peter To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message