Re: [PATCH 01/53] IB/qib: Add Kconfig

Roland Dreier
2009-11-20T00:02:34Z

A couple of random things, based on reading for a few minutes... will
try to get more in depth later...

> +++ b/drivers/infiniband/hw/qib/Kconfig
> @@ -0,0 +1,9 @@
> +config INFINIBAND_QIB
> + tristate "QLogic IB Driver"
> + depends on 64BIT && INFINIBAND
> + ---help---
> + This is a driver for QLogic PCIe QLE IB host channel adapters,
> + including InfiniBand verbs support. This driver allows these
> + devices to be used with both kernel upper level protocols such
> + as IP-over-InfiniBand as well as with userspace applications
> + (in conjunction with InfiniBand userspace access).

I think you need to say something about the relationship between ib_qib
and ib_ipath ... in fact the migration plan needs to be thought through
more overall I think. My suggestion would be to keep ib_ipath available
for ~one year, so plan on removing ib_ipath from the kernel around the
beginning of 2011... and in the meantime, the ib_qib merge should do the
following:

- in ib_qip Kconfig and also in updated ib_ipath Kconfig, mention that
there are two alternative drivers for older Qlogic HCAs.
- if both drivers are enabled, have ib_ipath take older HCAs; only put
new HCA support in ib_qib in that case. And print a warning that
ib_ipath is going away when it binds to an HCA.
- add something to Documentation/feature-removal about transition plan.

(The way the e1000 / e1000e driver split was handled might be
instructive to look at too)