is there any more to having a single interrupt drive multiple handlers than IRQF_SHARED?

[Robert P. J. Day]

On Thu, 26 Oct 2017, valdis.kletnieks at vt.edu wrote:

> On Thu, 26 Oct 2017 16:32:42 -0400, "Robert P. J. Day" said:
>
> >   now, i do realize that it can be used along with a unique dev_id
> > values to isolate a *particular* handler amongst a group of
> > handlers, but if one simply wants to trigger *all* handlers
> > registered for that interrupt, is there anything about that that's
> > tricky?
>
> You mean, other than the fact that multiple handlers for the same
> device damned well be coded to know that, and be aware of each
> other?  Locking, etc. and all the other Bad Juju that can happen
> when multiple drivers are all acting on one device.
>
> What problem is your colleague trying to solve by doing this?

  i wish i had more info, but i don't ... all i'm after is that this
is supportable via IRQF_SHARED and, when we chat again tomorrow, i
might be able to figure out whether this is appropriate. having the
handlers play nicely together will be phase two.

rday

p.s. is there an example of this usage somewhere in the kernel i can
point at? i vaguely recall that PCI does something like this, so i'm
off to take a look.

-- 

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Robert P. J. Day                                 Ottawa, Ontario, CANADA
                        http://crashcourse.ca

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