On 2012-10-23, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
>> Can it be guaranteed that it's going to be fast enough at high
>> baud-rates to prevent any gap between the first byte and subsequent
>> bytes?
>
> Possibly not for some protocols (or worse yet 'almost always' for
> some protocols).
>
> It's something to look at once the basic bits are in.
>
>> I now work for a company that has manufactured PC serial boards for
>> 25+ years, and we still get regular requests for that feature (and our
>> boards do support it -- though our Linux driver does not).
>
> In which case when we get to addressing this it will be good to make
> sure we cover your needs as well.
FWIW, in some products we're planning that will require support for
various industrial serial protocols, I'm leaning towards abandoning
the tty driver approach and writing a stand-alone character device
driver. The byte-stream oriented tty/line-discipline layer just
doesn't fit well when dealing with frame-oriented industrial protocols
that depend on things like 9th bit addressing and detecting
sub-millisecond inter-byte timeouts. When I add in the lack of
long-term stability in the tty API it seems like it might not be such
a bad idea to give up trying to make the tty abstraction fit a use
case that's just nothing like a teletype.
--
Grant Edwards grant.b.edwards Yow! Gibble, Gobble, we
at ACCEPT YOU ...
gmail.com
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
