Date: Fri, 05 Sep 1997 20:49:58 -0000 (GMT) From: Chris Dillon <cdillon@tri-lakes.net> To: Andrew Gordon <arg@arg1.demon.co.uk> Cc: freebsd-hardware@FreeBSD.ORG Subject: RE: Problems with 16650 UARTs Message-ID: <XFMail.970905212149.cdillon@tri-lakes.net> In-Reply-To: <Pine.BSF.3.91.970906010053.9191A-100000@server.arg.sj.co.uk>
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On 06-Sep-97 Andrew Gordon wrote: >I have a card with Startech 16C650CJ UARTs which is behaving rather >oddly. > >Initially, I was testing with stock 2.2.2-R, assuming that these beasts >were 16550-compatible by default. I later tried 2.2.2-STABLE, and >the latter with the explicit 16650 support from -current merged into >sio.c >(resulting in a sio.c which is the same as -current apart from some >stuff to do with COMCONSOLE). All give the same result. > >The behaviour is that the ports initially work OK, and will transmit >or receive continuously without problems, but after a short burst of >simultaneous transmission and reception, the receiver locks up >such that all received characters are lost silently (Tx continues to work >OK). Closing and re-opening the device unlocks it temporarily. >Most of my testing was at 115200, but it failed just as easily at 19200. >The problem occurs whether or not the port is configured for RTS/CTS >flow control. > >My initial test was with pppd on both ends (the other machine having >a conventional 16550). I then wrote a trivial dumb-terminal program >for testing (hacked to transmit 1000 copies of each character I >typed to generate enough traffic). > >While this could obviously be a faulty card, the fault is identical >on both ports (and the card has two separate 16C650CJ chips, plus >a minimal amount of TTL for address decode) so this seems unlikely. > > >Besides ideas for fixes, I would be interested in any pointers to >16650 datasheets (Altavista offers me several companies called >Startech that don't make UARTs, and lots of places that sell cards >with 16650s on them, but not the manufacturer!). > Bingo... I have been plagued with this same problem for some time, but thought it was just my lousy, clueless ISP at the root of it all (uses NT of all things... and Telebit Netblazer term servers. Are those any good?). I run 2.2-STABLE (recently cvsupped and made world) with userland ppp on an internal USR Sportster 33k6 with the port locked at 115200 using hardware flow control. I can be chatting on IRC, browsing web pages, and downloading some mail when all incoming data comes to a halt (even sometimes when just doing nothing). The only fix seems to be to kill the ppp session and dial in again (I usually just 'quit' and then run userland ppp all over again). I know that outgoing packets still work because anything I type in an IRC channel makes it out into the world.. I just don't get anything back. I don't know if this means much, but it almost ALWAYS happens when I get my mail, as this initially made me think it was just some anomaly between my ISP's mail server and the terminal server. It happened most often with Netscape's POP3 client and with popclient, but almost never with XFMail's POP3 client. --- Chris Dillon --- cdillon@tri-lakes.net --- Powered by FreeBSD, the best free OS on the planet ---- (http://www.freebsd.org)
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