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Date:      Sun, 23 Jul 1995 10:39:06 +0400 (MSD)
From:      =?KOI8-R?Q?=E1=CE=C4=D2=C5=CA_=FE=C5=D2=CE=CF=D7?= aka "Andrey A. Chernov, Black Mage" <ache@astral.msk.su>
To:        Terry Lambert <terry@cs.weber.edu>
Cc:        bde@zeta.org.au, hackers@freebsd.org, harry@hgac.com, jkh@violet.berkeley.edu
Subject:   Re: dial up at > 9600 baud
Message-ID:  <cVAwU4maH1@astral.msk.su>
In-Reply-To: <9507230530.AA24940@cs.weber.edu>; from Terry Lambert at Sat, 22 Jul 95 23:30:05 MDT
References:  <9507230530.AA24940@cs.weber.edu>

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In message <9507230530.AA24940@cs.weber.edu> Terry Lambert writes:

>> >PPP always connected at 9600 baud. Found that in getty.c the open() function
>> >blocks until carrier detected. This happens before the port is set up using
>> >the getty args. Changed getty to use non-blocking open(), then fall through
>> >to set up the port with getty args, and then wait for carrier using ioctl()
>> >similar to slattach. See attached diff file for getty.c in FreeBSD 2.0.5. 
>> 
>> I don't think, that waiting for carrier is right way.
>> Better way will be to open device as non-blocked,
>> then setup all tty flags (incl. speed), then reopen device
>> in blocked mode just before reading anything.
>> 
>> BTW, Bruce, is it possible now to switch to blocked
>> mode without reopening?

>No, it's not possible, since we are talking about whether the open flag
>is set or not for subsequent opens.

>The reason the ioctl() loses is taht it will prevent bidirection use
>of the port, with the getty open always having succeeded.


>I don't think I quite understand why the previous behaviour was a
>problem in the first place -- perhas the original poster could explain
>the rationale for his changes a bit better?


The problem: initial port speed 9600, getty speed 38400 f.e.,
port opened on carrier at 9600, modem detects it and set
connection to 9600 too, _then_ getty change port speed to 38400
confusing modem completely.

I understand that problem solves by locking port on 38400
initially, but it isn't nice solution, getty must able
to open port at correct speed setted in its flags.

-- 
Andrey A. Chernov        : And I rest so composedly,  /Now, in my bed,
ache@astral.msk.su       : That any beholder  /Might fancy me dead -
FidoNet: 2:5020/230.3    : Might start at beholding me,  /Thinking me dead.
RELCOM Team,FreeBSD Team :         E.A.Poe         From "For Annie" 1849



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