Re: [linuxsh-dev] SCI error handling

[YAEGASHI T. <yae...@ma...>]

In the article <E13...@pw...>,
NIIBE Yutaka <gn...@ch...> wrote:

> Good job.  Two comments:
> 
> (1) Why do you set TEI handler?  It's not worth to add it for XXX_IRQ
>     macros and the interrupt vectors, as we never use TEI interrupt in
>     the driver.  The driver is not the specification of the SCI, it's
>     the software which _use_ SCI.  If needed, people could get
>     hardware manual.  Just add for BRI is enough, I think.

Hmm.  So I would omit them.


> (2) Break handling
>     I think that we could find break condition with SCI when some
>     error occurs.  Then, call break handling routine.  Isn't it
>     possible?

Well, I'm not convinced of how it should behave itself when
multiple errors(and BREAK) occur simultaneously.  I suppose they
should be discarded except the most significant one, right?
(buffer overrun > BREAK > frame, parity error?)

Currently it reports all the detected errors to tty driver,
therefore too many errors could be generated.  And there are no
BREAK detection for SCI(w/o FIFO) port.

For the hardware problem, some port tends to generate so many
ERI or BRI, even when nothing is connected to the port(regarded
the input as continuous "L").  I suppose there are no way to
shut them up as long as RIE='1', so we need to introduce some
state management to prevent error notification flood to tty.

--
YAEGASHI Takeshi <yae...@ma...>