djs@nimbus3.UUCP (Doug) (02/12/90)
I'm having a problem with an AT&T 6386 running System V/386 R3.2 using an AT&T IPC-802 Intelligent Ports Card. A program has one of the ports open for reading and writing. While executing a write(2) system call of more than one byte (although I'm not sure that matters), something happens on the line and the process hangs. It can't be killed in this state. A scan of the manuals reveals no useful information. I guess I don't expect you to be able to tell me what is going wrong, although it would be nice :-). However, if someone could tell me how you go about diagnosing what is causing this problem it would be appreciated. A pointer to relevant documents or a place to poke around in the system would be nice. -- Doug Scofea Email: nimbus3!djs@cis.ohio-state.edu Phone:(614) 459-1889
kabra437@pallas.athenanet.com (Ken Abrams) (02/13/90)
In article <188@nimbus3.UUCP> djs@nimbus3.UUCP (Doug) writes: >I'm having a problem with an AT&T 6386 running System V/386 R3.2 using >an AT&T IPC-802 Intelligent Ports Card. A program has one of the >ports open for reading and writing. While executing a write(2) system >call of more than one byte (although I'm not sure that matters), >something happens on the line and the process hangs. It can't be >killed in this state. A scan of the manuals reveals no useful information. > I am having a similar problem and I think my hardware is probably the same as yours. I am using SCO Xenix, though, and the symptoms are slightly different (I CAN kill the process and wasn't able to track it down to a write operation). Nobody has yet been able to help me solve the problem but both SCO and AT&T are pointing the finger at the driver for the IPC-802. Since I am using Xenix, my driver came directly from CTC (board maker) and is not supported by AT&T. If your system is more than 9 months old, AT&T may have a new driver for the IPC-802. They scrapped the vendor's driver and wrote their own about then. I have been able to work around my problem by slowing my terminals down to 2400 baud, which is not a very good long term solution. AT&T has not been too impressed with the performance of the CTC board as evidenced by the fact that they don't use it in their new design. I posted a question similar to yours about a month ago and someone at AT&T (not in support) said he may be able to dig out some info. for me. So far, no response. I am about ready to scrap the IPC-802 but it will be a while due to budget. If you come up with anything concrete, I would like to hear about it. -- ======================================================== Ken Abrams uunet!pallas!kabra437 Illinois Bell kabra437@athenanet.com Springfield (voice) 217-753-7965
bogatko@lzga.ATT.COM (George Bogatko) (02/15/90)
At my site, our IPC-802 ports hang all the time. We just have to re-boot when they do. I've heard that Bell Tech. boards are cheaper and better. GB
hcj@lzsc.ATT.COM (HC Johnson) (02/17/90)
In article <293@pallas.athenanet.com>, kabra437@pallas.athenanet.com (Ken Abrams) writes: > In article <188@nimbus3.UUCP> djs@nimbus3.UUCP (Doug) writes: > >I'm having a problem with an AT&T 6386 running System V/386 R3.2 using > >an AT&T IPC-802 Intelligent Ports Card. A program has one of the > >ports open for reading and writing. While executing a write(2) system > >call of more than one byte (although I'm not sure that matters), > >something happens on the line and the process hangs. It can't be > >killed in this state. A scan of the manuals reveals no useful information. This is caused by two properties: 1. This is a blocking write, that is process is suspended until the write completes. 2. The driver has choses to sleep at a priority that is uninteruptable. This is a necessary evil; uninteruptable sleeps were meant for things like buffered IO to disk (and we know that disk never fail to complete!!) and interruptable sleeps allowed users to kill tty processes. Now we have communications activities that we dont want the user to kill at a bad time so the sleep is not interruptable. But since Comm lines fail in many ways, you are left with a process waiting for a never ending sleep. The only solution is REBOOT. Howard C. Johnson ATT Bell Labs =====NEW address==== att!lzsc!hcj hcj@lzsc.att.com
fmcgee@cuuxb.ATT.COM (~XT6561110~Frank McGee~C23~L25~6326~) (02/20/90)
In article <188@nimbus3.UUCP> djs@nimbus3.UUCP (Doug) writes: >I'm having a problem with an AT&T 6386 running System V/386 R3.2 using >an AT&T IPC-802 Intelligent Ports Card. A program has one of the >ports open for reading and writing. While executing a write(2) system >call of more than one byte (although I'm not sure that matters), >something happens on the line and the process hangs. It can't be >killed in this state. A scan of the manuals reveals no useful information. Make sure you have the IPC 3.0 drivers. If you don't, call the hotline (1-800-922-0354) and they can ship you a copy. Currently, there aren't any known bugs in the 3.0 driver. If you found something though, you should try and work it through the hotline. Hope you get it running, -- Frank McGee, AT&T Entry Level Systems Support attmail!fmcgee (preferred) att!cuuxb!fmcgee (those that can't reach attmail)