Date: Thu, 14 Feb 2002 04:19:23 +0100 From: Bernd Walter <ticso@cicely.de> To: Terry Lambert <tlambert2@mindspring.com> Cc: Bernd Walter <ticso@cicely.de>, Normand Leclerc <leclercn@videotron.ca>, freebsd-alpha@FreeBSD.ORG Subject: Re: Serial console drops dead Message-ID: <20020214031921.GA24983@cicely5.cicely.de> In-Reply-To: <3C6B1132.C0EAE93A@mindspring.com> References: <000501c1b494$c9c22d30$038c898e@dactyl> <20020213150404.GK23566@cicely8.cicely.de> <3C6AFB0C.B364DC97@mindspring.com> <20020214005919.GA24409@cicely5.cicely.de> <3C6B1132.C0EAE93A@mindspring.com>
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On Wed, Feb 13, 2002 at 05:21:54PM -0800, Terry Lambert wrote: > Bernd Walter wrote: > > On Wed, Feb 13, 2002 at 03:47:24PM -0800, Terry Lambert wrote: > > > On Wed, Feb 13, 2002 at 08:46:07AM -0500, Normand Leclerc wrote: > > > > I am having an annoying problem with my serial console. After a while > > > > (1 or 2 days) it drops dead. > > > > > > > > I have configured flags 0x30 for sio0 on FreeBSD 4.5 on my PC164sx > > > > computer. The serial terminal is a computer that is not always turned > > > > on. > > > > > > Use a null-modem cable, so that the computer doesn't have > > > any way of knowing (lack of DTR, RTS, CTS, DSR, DCD) that > > > you don't have the console turned on. > > > > FreeBSD consoles don't care for these lines. > > I usually open the seriel on my terminalserver only if I need and > > never had troubles. > > He's using an Alpha serial console with flags 0x30. > > I think that the Alpha serial console probe uses the > PAL interface to the serial port to do its thing (please > correct me, if I'm wrong), so even if FreeBSD's code > doesn't have a problem with it, that doesn't mean that > his SRM doesn't, or the FreeBSD/PAL probe/atach stuff > doesn't. It uses the PAL to know that the console is serial. The rest is mostly hardwired. The EB164 family uses 16550 at isa just like PCs. But he wrote about a problem after some days operating. He did not wrote about a problem with booting. If he had the situation would be clear - I don't have to tell you what a break condition means on a serial console? Unless he configured BREAK_TO_DEBUGGER FreeBSD should ignore, nevertheless it's the only reson I can imagine to cause these troubles. Unfotunately it's easy to irritate serial console service on some alphas. E.g. on PC164 you can't reboot from DDB. If you do FreeBSD will only write small blocks of data every second and only reads data if it wrote something. After init from SRM the magic returns to normal. The interrupt gets probed fine. I recently crashed a remote PC164 with such a broken console (unfortunately my MX box) and need to wait for local service :( It crashed right after I had found out that init is able to revive the console problem. > The real clue here would be a diff of the dmesg from > boots with and without the terminal turned on, but > since he's reporting problems with the terminal off at > boot, but no problems with it on at boot, it's pretty > indicative. > > Of course, the other option... leave the terminal on at > boot... is alsways there... 8-). It's most sensefull anyway. He has a computer doing that - I can't see a reason to use a computer for console serving and then turn it off. But that is a different issue. -- B.Walter COSMO-Project http://www.cosmo-project.de ticso@cicely.de Usergroup info@cosmo-project.de To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message
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