Re: [OctDev] [instrument-control]

[Andrius S. <and...@gm...>]

On Sat, Oct 20, 2012 at 8:07 PM, Juan Pablo Carbajal
<aju...@gm...>wrote:

> On Sat, Oct 20, 2012 at 3:11 AM, Andrius Sutas <and...@gm...>
> wrote:
> > On Wed, Oct 17, 2012 at 11:31 PM, Juan Pablo Carbajal
> > <aju...@gm...> wrote:
> >>
> >> Hello,
> >>
> >> I am observing weird behaviors and I couldn't pin down at which level
> >> things are going bad. Using instrument-control 0.1.0 from Forge.
> >> Running Ubuntu 12.04 64 bit
> >> Linux 3.2.0-32-generic #51-Ubuntu SMP Wed Sep 26 21:33:09 UTC 2012
> >> x86_64 x86_64 x86_64 GNU/Linux
> >>
> >> I am using serial communications. I am testing with a physical
> >> loopback (RxD connected to TxD) in this USB2Serial adapter
> >> https://www.sparkfun.com/products/718.
> >>
> >> Problem 1 [Ring bufffer?]:
> >>   s = serial (); # 8-N-1
> >>   srl_baudrate (s,9600);
> >>
> >>   srl_write(s,"hello")
> >>   ans = 5
> >>
> >>   char(srl_read (s,5))
> >>   ans = hello
> >>
> >>   char(srl_read (s,5))
> >>   ans = hello
> >>
> >>   char(srl_read (s,15))
> >>   ans = hellohellohello
> >>
> >>   char(srl_read (s,4))
> >>   ans = hell
> >>
> >>   char(srl_read (s,6))
> >>   ans = ohello
> >>
> >> It looks like as if the buffer is a ring buffer or is really big and
> >> filled with "hello". Maybe flushing the input after reading will solve
> >> the problem? Continued from the example before I got this
> >>
> >> Problem 2 [Hang after flush]:
> >>   srl_flush (s, 1)
> >>
> >>   char(srl_read (s,5)) # This blocks as expected but ...
> >>   srl_read: Interrupting...
> >>   ans =
> >>
> >>   srl_write(s,"hello")
> >>   ans =  5
> >>
> >>   char(srl_read (s,5)) # This also blocks!!!!
> >>   srl_read: Interrupting...
> >>   ans =
> >>
> >> The only way of getting things to work from this point on is to close
> >> the port and open it again.
> >>
> >> Can anybody reproduce this? any suggestions of tests to run to see
> >> whether the problem is at hardware level?
> >>
> >> I also tested with a virtual loopback (command "socat -d -d PTY:
> >> PTY:", this is simpler than the suggestion in the wiki. I can update
> >> that), I do not observe Problem 1, but I can't interrupt the second
> >> call to srl_read
> >>
> >> s = serial("/dev/ptmx", 9600);
> >> srl_write(s,"hello")
> >> ans =  5
> >> char(srl_read (s,5))
> >> ans = hello
> >> octave:5> char(srl_read (s,5))
> >> srl_read: Interrupting...
> >> srl_read: Interrupting...
> >> srl_read: Interrupting...
> >> srl_read: Interrupting...
> >>
> >>
> >> Thanks
> >>
> >>
> >>
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> >> _______________________________________________
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> >> Oct...@li...
> >> https://lists.sourceforge.net/lists/listinfo/octave-dev
> >
> >
> > UPDATE: I did replicate the bug eventually. I can not reproduce it
> > consistently, will look further into this behavior.
>
> Hi,
> Thanks for taking action.
>
> I tested again the following commands (Ubuntu 12.04 Linux
> 3.2.0-32-generic, FT232RL)
>
> Ring buffer
> http://agora.octave.org/snippet/Xd6x/
>
> Read hangs after flush
> http://agora.octave.org/snippet/mu7J/
>
> Weird data handling
> http://agora.octave.org/snippet/62x8/
>
> Still working unsatisfactorily.
>
> Cheers,
>
> JPi
>

A few minutes after this email I committed a possible fix, could you please
check it again? (don't forget to pkg install !)

Also, "weird data handling" is the same ring buffer problem. I assume "hang
after flush" is also related to the same bug.

I just tested the fix in ubuntu vm with two different adapters multiple
times and everything seems works :)