Should message signaled interrupts (MSI) work with Intel GMA 950?

Roland Dreier roland.list at
Thu Sep 6 13:04:59 PDT 2007

> Yeah, I haven't looked at it much, I'd have to check the specs to see if
> we can deliver an MSI that indicates what type of interrupt we're
> receiving.  If not, then the only benefit would be to avoid sharing I
> guess...

Current Linux only supports using one MSI vector, so you can't get more
than one interrupt with MSI.  You need MSI-X to use multiple vectors with
Linux right now.

Anyway the 945GM device in my system has:

    Capabilities: [90] Message Signalled Interrupts: Mask- 64bit-
Queue=0/0 Enable+

and the "Queue=0/0" part means that the device only supports one
MSI vector anyway.

So unfortunately no way to use separate interrupts for different events.

 - R.

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