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Re: serial port forever



The only reason for this behavior I can think of is that
we don't wait until all data is sent before we close the port.
This should be fixed a while ago in the serial driver for
devboard (with Linux 2.0 a.k. elinux) but it might not be fixed
in the latest devboard_lx (with Linux 2.4) where the driver isn't yet
updated to the improvements made in elinux (work in progress)

(Before closing the port we must wait for the DMA to finish,
 the fifo to be flushed and then wait one "char time" so that the
 last byte being shifted out really leaves the pin before we close
 the port)

/Johan

----- Original Message -----
From: Szabo, Tamas <Tamas.Szabo@xxxxxxx.com>
To: <dev-etrax@xxxxxxx.com>
Sent: Friday, October 05, 2001 4:23 PM
Subject: serial port forever


> Hello,
>
> It seems that I can understand linux or there is a serious problem with
> serial port (I hope the first). I wrote a few mail about my problem to the
> list but no answer recieved. I would like to use ser0 and ser2. I try to
> describe my method which is _very_ simple and it works between 2 PC:
>
> - On PC I start sermon or minicom
> - On devboard type: echo -n "blablabla" > /dev/ttyS0
>
> Unfortunately this is not work. The problem appears after a few characters
> (the number of characters depend on baudrate at 9600bps ~3-4 chars).
Usually
> the last byte(s) does not transmitted. This means somehow the last
> characters are cutted (even in middle of byte).
>
> I use:
> cris-dist 1.14
> devboard_lx 2.0.0
> linux 2.4.5
>
> I checked the mail list, but I did not find anybody who report this
problem,
> so I think if this problem only appears for me, this is my mistake. But I
> did not modified the sources or anyting else in packages above, and
compile
> without errors, then I download image to flash.
> And the result is not good. If I can not solve this probem, I can not
> develeop the my application.
>
> Can somebody help me? Peaseeeee!
>
> Sza2
>
>
>
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