Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!henry From: henry@utzoo.UUCP (Henry Spencer) Newsgroups: hacknews Subject: Re: dialin/dialout operational Message-ID: <5187@utzoo.UUCP> Date: Thu, 7-Mar-85 16:49:38 EST Article-I.D.: utzoo.5187 Posted: Thu Mar 7 16:49:38 1985 Date-Received: Thu, 7-Mar-85 16:49:38 EST References: <5186@utzoo.UUCP> Organization: U of Toronto Zoology Lines: 22 The "one lingering problem" alluded to in the previous message is now understood, and a fixed kernel will be tested Monday. It shouldn't affect normal operation of 5121. The problem was that any modem-status interrupt after a dialout device was opened but before it made a call successfully would abort the call, IF there wasn't a getty waiting on the same line. Roughly speaking. The modem-interrupt code noticed that carrier was off and nobody was waiting for it to be on, so it turned the line off (dropping DTR etc. to the modem). The real fun is that there is guaranteed to be a modem-status interrupt just after the dialout device is opened, since opening it raises RTS and the modem soon replies by raising CTS. So an outbound call got blown away almost instantly, unless there was also a getty waiting for carrier. The fix isn't hard, the modem-interrupt code just needs to know whether there's an uncompleted call in progress on the line. P.S. An overdue acknowledgement: Ron Gomes was the one who originally wrote the DH dialin/out code, although we've modified it a little. The bugs we've found have been our mistakes or the result of different circumstances. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry