[ofa-general] Oops in mthca

[Roland Dreier]

 > I discovered the following Oops while developing a patch to enable SRQ on HCAs with fewer than
 > 16 SG elements.

So is this oops with some version of your patch for limited SRQ
scatter entries applied?  It's hard to know exactly what is going
wrong but I suspect that if you get a device that allows more than 16
SRQ scatter entries, your patch passes that value for num_sg without
changing the declaration of rx_sge[] to have enough entries, so when
posting the receive request, the low-level driver goes off the end of
the array.

 > The root of this issue appears to be that ib_query_device(priv->ca, &attr)
 > reports an incorrect value for attr.max_srq_sge. The value that
 > ib_query_device returns is 28 (instead of 16 that I expected).

Why do you think the value 28 is incorrect?  Unfortunately I don't
have any PCI-X systems any more, but I don't see anything obvoius in
the mthca code that would make the value it returns for max_srq_sge
being wrong.

 - R.