public inbox for linux-hams@vger.kernel.org
 help / color / mirror / Atom feed
* RE: 300bps soundmodem notes and Broken Pipe
@ 2010-12-09 20:14 f6bvp
  2011-03-02  6:22 ` Tsutsumi Family
  0 siblings, 1 reply; 5+ messages in thread
From: f6bvp @ 2010-12-09 20:14 UTC (permalink / raw)
  To: oakie, linux-hams; +Cc: Bernard Pidoux

Hi,

A SIGPIPE signal is generated by Linux kernel when a frame cannot
be sent to destination for the connexion has timed out (broken or closed).

This signal is received by the program, here xmodem.
If the program does not handle this signal it may fall down.

This is why there is a possibility to declare that a specific
signal, say SIGPIPE, must be ignored. This is the purpose of line

signal (SIGPIPE, SIG_IGN);

that you may include at the beginning of the main program in the
file containing

main()

Look at the beginning of the file and localize a number of #include 
lines like :

#include <stdio.h>

You should add there the following line :

#include<signal.h>

Then, you should add the signal line at the beginning of the main 
program somewhere after variable declarations. For example :

main(int argc, char *argv[])
{
in c;
char *tab;

signal (SIGPIPE, SIG_IGN);

...

If you want you can send me privately a copy of the first 50 lines of
main() function code. I will help you doing the patch.


After saving the file you can compile xmodem and tell us if it works.

73 de Bernard, f6bvp


-----Original Message-----

Hello Bernard,

Thank you for picking up my question about "Broken pipe" issue and sending
your suggestion.

Please be patient for a while as I am not any computer language programmer
at all.

I read the source file of soundmodem and I believe the error message comes
from the second logprintf statement (line 368) in alsaio.c program.

---------------------------alsaio.c--------------------------------
static inline void iotxstart(struct audioio_unix *audioio)
{
         int err;

         if (snd_pcm_prepare(audioio->playback_handle) < 0) {
                 logprintf(MLOG_ERROR, "Error preparing tx.\n");
         }
         err = snd_pcm_start(audioio->playback_handle);
         if (err < 0)
                 logprintf(MLOG_ERROR, "snd_pcm_start in iotxstart: %s",
snd_strerror(err));
}
-------------------------------------------------------------------

Can you explain me the following questions concerning your suggestion?

1. Are you suggesting adding additional three lines in alsaio.c program?
If yes, which exact lines should I add?

2. What is the purpose and expected result of signal (SIGPIPE, SIG_IGN)
addition?

I am waiting your response soon.

Regards,

take



^ permalink raw reply	[flat|nested] 5+ messages in thread
* RE: 300bps soundmodem notes and Broken Pipe
@ 2010-12-06 10:24 f6bvp
  2010-12-07  1:11 ` Tsutsumi Family
  0 siblings, 1 reply; 5+ messages in thread
From: f6bvp @ 2010-12-06 10:24 UTC (permalink / raw)
  To: oakie, linux-hams

Hi,

You could try adding this in soundmodem :

#include<signal.h>
...
main()
...
...
signal (SIGPIPE, SIG_IGN);

73 de Bernard, f6bvp


-----Original Message-----
John,

Excellent note to the soundmodem beginners.

Concerning the soundmodem program, I often experience "broken pipe" errors
in high speed transmission setting with slow CPU machines and it looks like
one of the popular questions unexplained.

Can I have suggestion from the experienced linux-hams the proper ways to
fix?

Regards,

take

de JA5AEA


^ permalink raw reply	[flat|nested] 5+ messages in thread
* 300bps soundmodem notes
@ 2010-12-03  3:33 John Goerzen
  2010-12-03 15:00 ` 300bps soundmodem notes and Broken Pipe Tsutsumi Family
  0 siblings, 1 reply; 5+ messages in thread
From: John Goerzen @ 2010-12-03  3:33 UTC (permalink / raw)
  To: linux-hams

Hi folks,

Thanks to everyone for your help regarding getting 300 baud soundmodem 
going.  I have made it work now.  I've condensed the notes I received 
and posted them on my wiki at:

http://wiki.complete.org/LinuxPacketRadio#Soundmodem

Hopefully this will be helpful to others.

-- John
KR0L

^ permalink raw reply	[flat|nested] 5+ messages in thread
end of thread, other threads:[~2011-03-02  6:22 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2010-12-09 20:14 300bps soundmodem notes and Broken Pipe f6bvp
2011-03-02  6:22 ` Tsutsumi Family
  -- strict thread matches above, loose matches on Subject: below --
2010-12-06 10:24 f6bvp
2010-12-07  1:11 ` Tsutsumi Family
2010-12-03  3:33 300bps soundmodem notes John Goerzen
2010-12-03 15:00 ` 300bps soundmodem notes and Broken Pipe Tsutsumi Family

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox