Date: Tue, 11 Nov 1997 03:10:02 -0800 (PST) From: Bruce Evans <bde@zeta.org.au> To: freebsd-bugs Subject: Re: kern/4968: Problems working with Courier I-Modem Message-ID: <199711111110.DAA15487@hub.freebsd.org>
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The following reply was made to PR kern/4968; it has been noted by GNATS. From: Bruce Evans <bde@zeta.org.au> To: dgilbert@strike.velocet.ca, FreeBSD-gnats-submit@FreeBSD.ORG Cc: Subject: Re: kern/4968: Problems working with Courier I-Modem Date: Tue, 11 Nov 1997 22:05:35 +1100 >>Description: > > I have talked briefly about this problem once to one of the >developers. Basically, if ctsrts is on cuaa2, the modem receives fine, >but cannot transmit large files (using ppp). I think you mean crtscts. ctsrts is not an stty option. Apparently rts flow control of input works, but cts flow control of output doesn't (because the modem doesn't support it or isn't configured to support it or is broken or the cable is broken...). >If ctsrts is off, sending >files is fine (this is counter intuitive, but my own feeble explaination >is that the card can control drain interupts), but receiving files will >only work for some period of time before the kernel starts spitting out: > >Nov 7 03:16:24 wire1 /kernel: sio2: 54 more interrupt-level buffer overflows (total 788) >Nov 7 03:16:28 wire1 /kernel: sio2: 40 more interrupt-level buffer overflows (total 828) This message is unusual. It means that the system is overloaded with interrupt processing. Apparently the modem can keep up without input flow control (into it), but FreeBSD can't. FreeBSD has separate options rtsflow and ctsflow for each direction of flow control, so you can use the one that works. Bruce
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