Date: Sun, 10 Aug 1997 14:07:39 -0700 (PDT) From: Tom Samplonius <tom@sdf.com> To: Terry Lambert <terry@lambert.org> Cc: joerg_wunsch@uriah.heep.sax.de, hackers@freebsd.org Subject: Re: ISDN drivers/cards Message-ID: <Pine.BSF.3.95q.970810135612.5484B-100000@misery.sdf.com> In-Reply-To: <199708101948.MAA11188@phaeton.artisoft.com>
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On Sun, 10 Aug 1997, Terry Lambert wrote: > > As Tom Samplonius wrote: > > > > > > going from TA to TA or TA to Router, I'd love to see an internal card that > > > > doesn't use 16550's that I can put in my freebsd machine and get good > > > > > > This can be improved a lot. Most TAs support a 230400bps rate, but > > > FreeBSD does not. > > > > Well, that's not the first time you're spreading this misinformation > > around: FreeBSD _would_ support this rate (basically), but the under- > > lying hardware doesn't. Who wrote the above? They didn't CC it to me. Also, they certainly didn't respond to my much earlier messages about 230400 support. Also, the underlying hardware DOES support that rate. The 16670 does. Support was added to current to probe this uart (see list archives for the bitching when it broke things). There are also other uarts and other cards that support this rate. I suggest that you stop spreading misinformation that the hardware doesn't support 230400bps. It does. 16670 and better uarts do. > > If you've got a card where you could double the oscillator frequency, > > simply do it, and FreeBSD will support 230400 bps (but call it 115200 > > still). > > Didn't Tom post a while back about needing a driver for a faster UART, > but not knowing how to pass the information down? > > Was that Tom? Nope, it was somone else. It seems that some the card drivers are just re-using the low speed indicators to actually set >115200 baud rates. > I remember that *someone* had just done this, and no one responded > to the request for how to set 230400. > > There *is* a B230400 in termios.h, if anyone is interested... I > didn't respond to the initial request because I thought Bruce Evans > or Mike Smith would answer the question. > > > > > FreeBSD-current now detects the 16670 UART that supports 230400 (and > > > faster. But it doesn't seem possible to set a port to 230400. > > > > Ah, that's what you mean. So, if they support 230 kbps, they must > > have left the way it used to be done in a 8250-compatible UART. (The > > divisor 1 already yielded 115200. Are they using divisor 0 now? :-) > > If they are, they are using it to say "look elsewhere for your divisor"; > probably they just have another divisor register that someone needs to > teach sio about... like someone with a 16670 UART to play with. 8-). Not really relevant. Can a port be used at >115200 under FreeBSD? The answer seems to be: - Hack the hardware to double the clock rate, so that 115200 is actually 230400. This only works with uarts that have an accessible crystal. - Use a driver and card that is hacked to re-use low speed baud rate indicaters to actually specify a higher rate (ex. 150 bps is acactually 230400). > > Terry Lambert > terry@lambert.org > --- > Any opinions in this posting are my own and not those of my present > or previous employers. > > Tom
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