Re: ttyS1 hangs, cua1 works fine

Harald Koenig (koenig@tat.physik.uni-tuebingen.de)
Sun, 29 Mar 1998 17:42:47 +0200


On Mar 28, mlord wrote:

> Here is stty -a </dev/ttyS1 from just after booting:
>
> speed 9600 baud; rows 45; columns 80; line = 0;
> intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
> eol2 = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W;
> lnext = ^V; flush = ^O; min = 1; time = 0;
> -parenb -parodd cs8 hupcl -cstopb cread clocal -crtscts
^^^^^^
clocal is set, that's ok.

> Here it is again while pppd is running:
>
> speed 115200 baud; rows 45; columns 80; line = 3;
> intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
> eol2 = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W;
> lnext = ^V; flush = ^O; min = 1; time = 0;
> -parenb -parodd cs8 hupcl -cstopb cread -clocal crtscts
^^^^^^^
clocal is set, that's needed to get hardware handshake (crtscts).
but when pppd is stopped, this has to be reset.
are you killing pppd with SIGKILL (-9) by any chance ?

On Mar 28, mlord wrote:

>
> UPDATE: I hacked the source code for stty
> to open /dev/ttyS1 with O_NONBLOCK, which works,
> and now see the following after pppd stops:
>
> speed 115200 baud; rows 92; columns 80; line = 0;
> intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
> eol2 = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase =
> ^W;
> lnext = ^V; flush = ^O; min = 1; time = 0;
> -parenb -parodd cs8 hupcl -cstopb cread -clocal crtscts
^^^^^^
> Does this mean anything to anybody?

yep, clocal isn't set, so the open() will block. use

stty clocal < /dev/ttyS1

with your new stty binary to change this (or fix pppd ir you kill-pppd method).

Harald

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