Serial blocking read

Christopher Faylor
Fri Dec 15 18:09:00 GMT 2000

I think this is coming from but I don't know for
sure.  Can you provide a unified diff?  A complete unified diff will
show the filename and give a little more context.

The contributing link on should give you some pointers on how
to do this and how to provide a patch.


On Fri, Dec 15, 2000 at 05:38:09PM -0800, Dan Morris wrote:
>Has anyone else had problems with serial port reads blocking even when
>O_NONBLOCK is passed to _read in the 1.1.6-1 DLL?
>I noticed that my reads were appropriately non-blocking most of the time, but
>blocked whenever "overlapped_armed" was set, because in this case raw_read
>never finds out how many bytes are in the serial port's buffer.  This patch
>seems to fix the problem for me :
>>       if (overlapped_armed) {
>>           if (!ClearCommError (get_handle (), &ev, &st))
>> 	          goto err;
>>           else if (st.cbInQue)
>>             inq = st.cbInQue;
>>       }
>If anyone else has found a better solution to this problem, let me know...
>otherwise perhaps this patch will fix things.
>Dan Morris
>Tiqit Computers

--                        Red Hat, Inc.  

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