Good suggestion and in fact that's what I had to do to get RTS
deasserted after open but unfortunately it doesn't help between
deassertion and assertion of RTS.
Thanks again,
john
[EMAIL PROTECTED] wrote:
>
> This feels like a timing problem. Try putting a sleep(5); after you
> deassert RTS in initialization. Probably, sleep(1); would be enough, or
> even nanosleep, but just to be sure we give it a fair test...
>
> Lawson
> >< Microsoft free environment
>
> This mail client runs on Wine. Your mileage may vary.
>
> On Wed, 13 Oct 1999, John Florence wrote:
>
> > I am using /dev/ttyS.
> >
> > Both machines have 16550A uarts.
> >
> > I use tcdrain before deasserting RTS.
> >
> > My understanding of CRTSCTS is that the DCE device uses CTS to start
> and
> > stop the DTE device Tx to prevent buffer overrun. My DCE device won't
> > grant CTS if it can't receive but expects the DTE to drop RTS to signal
> > end of message.
> >
> > The symptoms on the Dell laptop are:
> > I successfully deassert RTS in initialization. I do this since RTS goes
> > high on open of the serial device. When I try to assert RTS nothing
> > happens. The application thinks all is ok and procedes to wait for
> CTS.
> >
> > I'm not familiar with TIOCSERGETLSR but will look into it.
> >
> > Thanks,
> > john
> >
> > [EMAIL PROTECTED] wrote:
> > >
> > > I am still using SlackHat with 2.0.38 and retrofits, so I can't
> comment
> > > on 2.2.x, except I don't think /dev/cua is supported anymore. You
> > > should be right if you use /dev/ttyS.
> > >
> > > I don't see anything wrong about using TIOCMGET/TIOCMSET. CRTSCTS
> would
> > > do the same automagically, but it makes some requirements about the
> > > other signals that might greatly inconvenience you. Depending on the
> > > size of the FIFO in the UART, you might need to read the LSR with
> > > TIOCSERGETLSR to check that all characters have gone out on the line
> > > before you drop RTS. I'm pretty sure write() won't block on that, so
> if
> > > the box that works has a 16450, and the one that doesn't has a
> 16550A,
> > > that may well be the trouble.
> > >
> > > It would help if you told us _how_ it doesn't work (symptoms, please
> :-)
> > >
> > > Lawson
> > > >< Microsoft free environment
> > >
> > > This mail client runs on Wine. Your mileage may vary.
> > >
> > > On Wed, 13 Oct 1999, John Florence wrote:
> > >
> > > > I have an application that needs the ability to assert RTS before
> > > > sending a 700 bit message and to deassert RTS after CTS is granted
> and
> > > > the message is transmitted. I use ioctls and TIOCMGET/TIOCMSET to
> > > > control RTS. The application seemed to run fine on a Compaq running
> an
> > > > old version on Slackware (kernel 1.2.8) but won't run on a Dell
> laptop
> > > > running Red Hat 6.0. I looked at the serial device driver in the
> > > > Slackware and the Red Hat systems and they are the same.
> > > >
> > > > Has anyone else had problems with Red Hat, kernel 2.2.5-15, and/or
> > > > laptops? Comments on my technique are also welcome - I know that I
> > > > should write a device driver but for now I'm just trying to get
> > > > something working.
> > > > --
> > > >
> > >
>
> > > > John Florence, Mathematician, VSS Group, 25-162 Phone:
> > > 240-228-6685
> > > > JHU/APL, Johns Hopkins Road, Laurel, MD 20723 FAX:
> > > 240-228-6663
> > > >
> > >
> [EMAIL PROTECTED]
> > > >
> > > > -
> > > > To unsubscribe from this list: send the line "unsubscribe
> linux-serial"
> > > in
> > > > the body of a message to [EMAIL PROTECTED]
> > > >
> > >
> > > ___
> > > Get the Internet just the way you want it.
> > > Free software, free e-mail, and free Internet access for a month!
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> >
> > --
> >
>
> > John Florence, Mathematician, VSS Group, 25-162 Phone:
> 240-228-6685
> > JHU/APL, Johns Hopkins Road, Laurel, MD 20723 FAX:
> 240-228-6663
> >
> [EMAIL PROTECTED]
> >
>
> ___
> Get the Internet just the way you want it.
> Free software, free e-mail, and free Internet access for a month!
> Try Juno Web: http://dl.www.juno.com/dynoget/tagj.
--
John Florence, Mathematician, VSS Group, 25-162 Phone: 240-228-6685
JHU/APL, Johns Hopkins Road, Laurel, MD 20723 FAX: 240-228-6663
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