irq256 ????

mike at sentex.net mike at sentex.net
Thu Oct 9 23:42:43 UTC 2008


On Thu, 9 Oct 2008 23:49:54 +0200, in sentex.lists.freebsd.questions
you wrote:
>> 
>> What's that? (world and kernel are in sync)
>
>It is an MSI-style interrupt [MSI=Message Signaled Interrupt] (available on
>PCI-E devices and a few PCI/PCI-X devices.) They get allocated fake
>irq-numbers starting at 256.
>
>I.e. it is a feature, and a bug or indication of any problem.

And you can see what devices are MSI capable with
pciconf -lvc

e.g

em0 at pci0:5:0:0: class=0x020000 card=0x348d8086 chip=0x108c8086
rev=0x03 hdr=0x00
    vendor     = 'Intel Corporation'
    device     = '82573E Intel Corporation 82573E Gigabit Ethernet
Controller (Copper)'
    class      = network
    subclass   = ethernet
    cap 01[c8] = powerspec 2  supports D0 D3  current D0
    cap 05[d0] = MSI supports 1 message, 64 bit enabled with 1 message
    cap 10[e0] = PCI-Express 1 endpoint 

	---Mike


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