Message Signalled Interrupts Question ...

[Scott Long]

Wilkinson, Alex wrote:
>     0n Fri, May 11, 2007 at 03:49:01AM +0100, Rui Paulo wrote: 
> 
> bge(4) has MSI support but not em(4) ... bizarre.
> 
>   bge0 at pci5:2:0:  class=0x020000 card=0x12bc103c chip=0x169614e4 rev=0x03 hdr=0x00
>       vendor     = 'Broadcom Corporation'
>       device     = 'BCM5782 Broadcom NetXtreme Gigabit Ethernet for hp'
>       class      = network
>       subclass   = ethernet
>       cap 01[48] = powerspec 2  supports D0 D3  current D0
>       cap 03[50] = VPD
>       cap 05[58] = MSI supports 8 messages, 64 bit 
>   em0 at pci5:4:0:   class=0x020000 card=0x10018086 chip=0x10268086 rev=0x04 hdr=0x00
>       vendor     = 'Intel Corporation'
>       device     = '82545GM Gigabit Ethernet Controller'
>       class      = network
>       subclass   = ethernet
>       cap 01[dc] = powerspec 2  supports D0 D3  current D0
>       cap 07[e4] = PCI-X 64-bit supports 133MHz, 2048 burst read, 1 split transaction
> 
>  -aW
> 

Beware that just because a chip reports MSI support doesn't mean that it
actually works.  MSI is still relatively new technology, and one that is
only recently getting real-world testing and validation.  We will be
adding and maintaining driver quirks to selectively disable MSI for a
long time to come.

Scott