termios problem - also in prerelease 3

Angelo Fraietta angelo_f at bigpond.com
Thu May 22 01:11:34 UTC 2003


I have experienced this problem again, now with the prerelease 3. The 
task writing to the serial port sometimes locks up.

It has nothing to do with receiving on the same port as I did not have 
anything going into that port. I was however, disabling and reenabling 
interrupts in one of the tasks, and this may have something to do with 
it. I am now just using that port as a diagnostic port and have 
subsequently disabled writing to it.

Joel Sherrill wrote:

>Angelo Fraietta wrote:
>  
>
>>I have found the problem.
>>The PC that I am using is a very old PC, which I think is not using a
>>16550 UART and probably not full duplex. Everything worked fine at
>>most times, however, if data was received at the same time, the Tx
>>seemed to get lost, and so the transmit function never returned.
>>    
>>
>
>Is there a real way to fix this without kludging something or is this
>an ugly thing that must just be lived with. :(
>
>  
>
>>I overcame this by setting the retry time-out in the application that
>>communicates with my RTEMS device to a slower speed. This overcame the
>>problem.
>>
>>I want to say, however, the problem did not occur on my embedded
>>device (DIMMPC) because I think the UART is full duplex.
>>
>>Andrew N. Maximov wrote:
>>
>>    
>>
>>>Hello Angelo,
>>>Thursday, August 08, 2002, 2:23:30 AM, you wrote:
>>>AF> Did you ever find the problem to this? I am having a similar
>>>problem now
>>>AF> on the pc386
>>>
>>>      
>>>
>>>>>There is some problems with termios. System hangs after I try
>>>>>to output to console more than 64 characters. My configuration:
>>>>>HARDWARE: MC68MH360
>>>>>RTEMS: RTEMS-4.5.0
>>>>>BSP: m68k
>>>>>
>>>>>          
>>>>>
>>>My test is not correct. It calls printf function from timer's
>>>service
>>>routine. It is wrong. Because timer's routine is called from
>>>interrupt
>>>handler. If you need to output some debug info from isr, you must
>>>use
>>>printk. I have no problems with RTEMS-4.5.0 on MC68MH360, now. Our
>>>system based on RTEMS works about four months uninterruptedly. But
>>>we
>>>use RTEMS on pc386 for test's purpose only.
>>>
>>>      
>>>
>>--
>>Angelo Fraietta
>>
>>PO Box 859
>>Hamilton NSW 2303
>>
>>Home Page
>>
>>http://www.users.bigpond.com/angelo_f/
>>
>>There are those who seek knowledge for the sake of knowledge - that is CURIOSITY
>>There are those who seek knowledge to be known by others - that is VANITY
>>There are those who seek knowledge in order to serve - that is LOVE
>>    Bernard of Clairvaux (1090 - 1153)
>>    
>>
>
>  
>

-- 
Angelo Fraietta

PO Box 859
Hamilton NSW 2303

Home Page


http://www.users.bigpond.com/angelo_f/

There are those who seek knowledge for the sake of knowledge - that is CURIOSITY
There are those who seek knowledge to be known by others - that is VANITY
There are those who seek knowledge in order to serve - that is LOVE
    Bernard of Clairvaux (1090 - 1153)


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