PCI speed

[Warner Losh]

On Fri, Mar 3, 2017 at 3:34 PM, Dirk-Willem van Gulik
<dirkx at webweaving.org> wrote:
> Forgive me my ignorance - but for some cards - pciconf(8) nicely lists the speed of the bus:
>
>> ciss0 at pci0:12:0:0:      class=0x010400 card=0x3243103c chip=0x323a103c rev=0x01 hdr=0x00
> ...
>>     cap 10[70] = PCI-Express 2 endpoint max data 128(256) RO NS
>>                  link x4(x8) speed 5.0(5.0)
>>     cap 11[ac] = MSI-X supports 16 messages, enabled
>>                  Table in map 0x10[0x1c2000], PBA in map 0x10[0x1c4000]
>>   PCI-e errors = Correctable Error Detected
>>                  Fatal Error Detected
>>                  Unsupported Request Detected
>
> and that matches exactly with what it is. While for other cards it does not seem to report that:

So you have a x8 card in a x4 slot. Hope that's OK. It's also
reporting errors on the PCIe link level. That doesn't sound too
correct.

>> mpt4 at pci0:7:8:1:        class=0x010000 card=0x10b01000 chip=0x00301000 rev=0x08 hdr=0x00
> ....
>>     cap 01[50] = powerspec 2  supports D0 D1 D2 D3  current D0
>>     cap 05[58] = MSI supports 1 message, 64 bit
>>     cap 07[68] = PCI-X 64-bit supports 133MHz, 2048 burst read, 8 split transactions
>>     cap 00[70] = unknown
>
> and in fact seems to mis report the bus - this is a  PCIe Gen 2 x4 bus with a x8 Connector Width
> holding  a LSI 22320SE Ultra320 SCSI dual channel PCIe X4 card.

> How should one interpret this ?

That's odd. I'd have expected it to report correctly... It does for us at work.

What version of FreeBSD?

Warner