irq sharing not permitted - comedi's or RTLinux/RTAI's limitation?

Dear comedi users,

  As I read the comedi source code, I discovered that comedi does not allow
a realtime interrupt handler to share irq with non-realtime handlers. Is it
that it is impossible to share interrupt under RTLinux/RTAI, or it is
comedi's limitation?
  I have searched through the archive of the mailing lists (RTLinux & RTAI).
In RTLinux, I found a thread that asked how to share irq, but the guy who
answered gave example codes of NON-SHARED interrupt handler as answer. In
RTAI, I found postings that referred to irq sharing
(https://mail.rtai.org/pipermail/rtai/2003-January/002328.html), but I did
not see a working example. In any of the mailing list, no one reported a
success in sharing irq by RT and non-RT handlers. I myself have never
succeeded, either.
  Am I trying to do what is not permitted in the first place? I am sure that
comedi developers have worked on this issue meticulously, thus I believe
they know the answer. Hope someone will clarify.
Regards,
Taku Ogasawara

Received on 2003-05-16Z01:21:54