Console driver that needs extra TIMER

Joel Sherrill joel.sherrill at oarcorp.com
Thu Aug 14 14:23:15 UTC 2014


On 8/14/2014 9:20 AM, Gedare Bloom wrote:
> On Thu, Aug 14, 2014 at 10:15 AM, Joel Sherrill
> <joel.sherrill at oarcorp.com> wrote:
>> On 8/14/2014 9:11 AM, Kolja Waschk wrote:
>>> Hi,
>>>
>>> I'm developing a DMA-based UART driver for Blackfin. It requires an
>>> extra timer to trigger data processing after a transmission ended. This
>>> increases the amount of timers required by every application that uses
>>> it for the console.
>> Don't you get an end of DMA TX interrupt?
>>> E.g. most of the tests won't even start without modifications. So
>>> effectively I have to fall back to a polling driver for console if I
>>> want to run the tests unmodified, or is there any mechanism to generally
>>> increment the amount of timers for all tests?
>> I don't think so. There are some BSP hooks for various features and
>> default number
>> of termios ports. But nothing specific to an object.
>>
> If you are working with rtems.git, you could probably just add another
> BSP setting in confdefs.h for this and push the patch out for
> inclusion in RTEMS. Something like CONFIGURE_BSP_TIMERS() that gets
> added into CONFIGURE_MAXIMUM_TIMERS(). If you need more guidance how
> to do this just ask.
>
>> I suppose one could be added but for orthogonality, it would make me wonder
>> why we wouldn't also let you add a BSP factor on every Classic API object.
>> Just thinking out load.
> Joel, what kind of load?
out loud. :)
> There are probably only a few object-types that a BSP might need to
> reserve for use, but it may be worth considering.
Task, semaphore, message queue come to mind. Obviously he needs a timer
but that makes sense, I always use the example of timeouts in communications
protocols.

Hmm.. if we add message queue, we need to remember the buffer side of that.
> -Gedare
>>> Thanks,
>>> Kolja
>>>
>>>
>>>
>>>
>>>
>>> _______________________________________________
>>> devel mailing list
>>> devel at rtems.org
>>> http://lists.rtems.org/mailman/listinfo/devel
>> --
>> Joel Sherrill, Ph.D.             Director of Research & Development
>> joel.sherrill at OARcorp.com        On-Line Applications Research
>> Ask me about RTEMS: a free RTOS  Huntsville AL 35805
>> Support Available                (256) 722-9985
>>
>> _______________________________________________
>> devel mailing list
>> devel at rtems.org
>> http://lists.rtems.org/mailman/listinfo/devel

-- 
Joel Sherrill, Ph.D.             Director of Research & Development
joel.sherrill at OARcorp.com        On-Line Applications Research
Ask me about RTEMS: a free RTOS  Huntsville AL 35805
Support Available                (256) 722-9985




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