termios

[Joel Sherrill]

Thomas Doerfler wrote:
> 
> Hello,
> 
> I think you refer to the loop starting with
> 
>                 while (tty->rawInBuf.Head != tty->rawInBuf.Tail) {
> 
> in function "fillBufferQueue" in termios.c.
> 
> IMHO a solution would be to limit the loop to the cases, when
> the variable "wait" ist still TRUE, so a replacement for the
> upper line would be
> 
>                 while (wait && (tty->rawInBuf.Head != tty->rawInBuf.Tail)) {

I think either will work but changing the semantics of the checks being
made
separately scares me a bit without doing more analysis.

I think Wolfram's solution is correct and less likely to perturb things.

Can one of you file a PR once the patch is tested?

FWIW my first job out of college was porting the System V TTY driver
to an embedded environment.  It was an intelligent serial controller
and the card pretty closely mapped section 2 system calls.  The code
was incredibly complicated and the RTEMS termios driver is a piece of
cake to read compared to that. :)

--joel


> wkr,
>         Thomas Doerfler.
> 
> > Hello,
> >
> > we are struggling with the termios system in the moment and we need the
> > help of the community.
> > either there is a missunderstanding of cannonical processing by us or a
> > real bug in the termio system.
> > the function fillBufferQuue() is responsible to transfer from raw input
> > buffer into cooked buffer and all the control character processing is
> > handled by iproc(). when iproc() signals a completed line by returning a
> > one, fillBufferQueue does not return to the caller with this line in the
> > cooked buffer, but remains in its loop and appends all further
> > characters (after cannonical processing) to the cooked buffer. IMHO
> > fillBufferQueue should return immediately after an NL, EOF, EOL or EOL2
> > was added to cooked buffer.
> >
> > this behaviour could be accomplished by adding a break instruction after
> > the wait = 0; instruction after calling siproc() in cannonical processing.
>
> > --
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> >
> > Wolfram Wadepohl
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> 
> --------------------------------------------
> IMD Ingenieurbuero fuer Microcomputertechnik
> Thomas Doerfler           Herbststrasse 8
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-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel at OARcorp.com                 On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
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