Re: if i deselect PCIEPORTBUS, why are iwlwifi PCIE modules still being compiled?

[Johannes Berg <johannes@sipsolutions.net>]

On Tue, 2014-05-20 at 03:49 -0400, Robert P. J. Day wrote:
>   quite possibly a silly question (which has never stopped me before),
> but in perusing the PCIE code in the kernel source, i was looking for
> sample code to demo in a classroom setting and picked on
> drivers/net/wireless/iwlwifi/pcie, which i was *assuming* was
> PCIE-dependent -- specifically, i was going to demo the Advanced-N
> 6235 PCIE wifi card on an intel galileo board.
> 
>   but i thought it was a bit strange that the pcie/ subdirectory there
> doesn't seem to depend on PCIEPORTBUS. as a test, i deselected
> PCIEPORTBUS in a configuration and did a rebuild, and the source in
> the pcie/ directory was recompiled.
> 
>   am i misunderstanding the function of the kernel config variable
> PCIEPORTBUS? i notice that .../iwlwifi/Makefile includes the line:
> 
>   iwlwifi-objs  += pcie/drv.o pcie/rx.o pcie/tx.o pcie/trans.o
> 
> which simply compiles those files with no regard to dependency. can
> someone clarify this? thanks.

The whole driver depends on CONFIG_PCI, maybe it should depend on
something more PCIe specific, but that wasn't easy to sort out, and the
APIs it needs aren't PCIe specific afaict.

johannes