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    <p>Three things you might check:</p> <h2>Canonical mode / non canonical mode mixup 1</h2> <p>You are mixing the canonical mode and the the non-canonical mode stuff:</p> <pre><code>ptr-&gt;serialdev.c_lflag = ( ICANON ); // ... ptr-&gt;serialdev.c_cc[VMIN] = 1; </code></pre> <p>The <code>termios(3)</code> manpage states about VMIN:</p> <blockquote> <p><strong>VMIN</strong> Minimum number of characters for <strong>non</strong>-canonical read.</p> </blockquote> <p>So clearly your timeout will not work the way you think.</p> <h2>Canonical mode / non canonical mode mixup 2</h2> <p>Additionally the manpage says further below:</p> <blockquote> <p>These symbolic subscript values are all different, except that VTIME, <strong>VMIN</strong> <strong>may</strong> have the same value as VEOL, <strong>VEOF</strong>, respectively. In non- canonical mode the special character meaning is replaced by the timeout meaning. For an explanation of VMIN and VTIME, see the description of non-canonical mode below.</p> </blockquote> <p>So please check if the definitions of these constants are different for your two platforms. It might be, that the EOL/EOF logic might be spoiled by the wrong setting. Both EOL and EOF migh cause a return from <code>read</code>.</p> <h2>Non-initialized <code>c_cc</code></h2> <p>Your code does not show a proper initialization of the <code>c_cc</code> array. You neither read the existing settings not provide suitable defaults for the values required for canonical modes. The code shown so far does not even clear the values. Therefore unpredictable values might be used. </p>
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    1. POreading serial port blocks for unknown reason
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    1. COHi A.H. , you are aright about the VMIN. It's not needed in CANONICAL mode, so I have edited the question by commenting it. But about initializing the struct, you can see that I am zeroing my structure which contains the termios struct, so I am initializing the entire struct to zero, I am not leaving it hanging.
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    2. CO@aditya: Sorry, I didn't notice the `bzero`. But that strengthens the point, that the required control characters for canonical mode are not configured.
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    3. COVery true, they should have been initialized. Just to point out, I did actually initialize the VEOL,VEOL2 and VEOF in one of my trials, since I thought read() was blocking bcos it wasnt getting the default terminal '\n', but to no avail.
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