Elsa MicroLink 33.6TQV on HP-UX 10.20 with vgetty

• Messages sorted by:[ date ][ thread ][ subject ][ author ]

Hi,

Lutz Jaenicke wrote:
> 11/27 12:17:59 0p0 initializing Elsa voice modem
> 11/27 12:18:00 0p0 waiting...
> 11/27 12:18:01 0p0 waiting for ``RING_''
[..]
> 
> While digging through the source code, it seems, that "select()" errornously
> returns with the "ready to read" flag set. I checked with a "read()" directly
> after the select in io.c:wait_for_input(), that no data is ready for reading
> (read returns 0). This effect only happens, after the termio is reprogrammed
> in voice/libvoice/init.c:voice_init(). I have no experience with programming
> the serial line, but the problem seems to be related to the c_cc adjustments.

I dimly remember that we have seen this on some other platform as well.
It seems to be related to setting VTIME to something > 0.

At that time, we did not fix it, because nobody had time (and partly
because I think that's a bug -- select() should return if there is 
*DATA*, not "if a subsequent read() won't block" - but then, select() 
isn't standardized *that* well...)

Does somebody remember *which* platform exhibited this problem before, and
how we solved this / worked around it?

> I have additional problems with sending audio data to the modem (buffer
> underflow etc) which occur later on, but may be this is related to the 
> problem above.

I don't think so. This is more likely a serial driver problem, but
someone more "in the know" would have to look at the logs.

> Is anybody running a vgetty/Elsa combination on HP-UX 10.20? How can select
> return, when read() returns 0 (= no character to be read)? 

Uh, this is easy to understand: "read() *does not block*" -- so the
condition "return if a subsequent read() won't *block*" is met. It just
depends on how you expect select() to behave...

> Where can I find
> additional documentation for tracking down the problem?

Source... :-/

> PS. Should I have spent more money? At home my Zyxel E2864ID works fine
> with Linux, even with the additional memory for fax receipts without PC :-)

I don't think a different modem would have made a difference. A different
operating system maybe :-)

gert

-- 
USENET is *not* the non-clickable part of WWW!
           //www.muc.de/~gert/
Gert Doering - Munich, Germany      gert@greenie.muc.de
fax: +49-89-35655025    gert.doering@physik.tu-muenchen.de
.