could the [x86] Kconfig content for PCI be cleaned up at all?

digging through the current PCI code and Kconfig files and it seems
like some of that could be made simpler, but i'm willing to be convinced otherwise.

first, from arch/x86/Kconfig, rather than simply sourcing the file
"drivers/pci/Kconfig" (as is done with many other drivers directories), that Kconfig file defines:

menu "Bus options (PCI etc.)"

config PCI
bool "PCI support"
default y
... snip ...

and later on, sources the Kconfig files for PCI and PCIe individually:

source "drivers/pci/pcie/Kconfig"

source "drivers/pci/Kconfig"

and even further down, finally sources the file for PCI hotplug after PCMCIA:

source "drivers/pcmcia/Kconfig"

source "drivers/pci/hotplug/Kconfig"

given the dependencies, could all of this not be encapsulated in the top-level Kconfig files under drivers/pci?

next, in drivers/Makefile, pci code is pulled in with the single
statement:

  obj-$(CONFIG_PCI)               += pci/

given that, can't one drop all the "depends on PCI" directives from the file drivers/pci/Kconfig? or just wrap the whole file in a "if PCI" test? (unless there's something i'm missing here.)

and could the same thing not be said for the pcie/ subdirectory?
drivers/pci/Makefile contains the line:

  obj-$(CONFIG_PCIEPORTBUS) += pcie/

with the dependency in drivers/pci/pcie/Kconfig:

config PCIEPORTBUS
bool "PCI Express Port Bus support"
depends on PCI

suggesting that drivers/pci/pcie/Kconfig could also be simplified quite a bit by dropping redundant dependency directives.

thoughts?

Quoted 4 lines · Robert P. J. Day

digging through the current PCI code and Kconfig files and it
seems like some of that could be made simpler, but i'm willing to be convinced otherwise.

I'm sure it could be cleaned up, and it would be great if you did!

I don't know the reason why all the arches source drivers/pci/pcie/Kconfig directly; it seems like that should be done from drivers/pci/Kconfig.

Quoted 4 lines · Robert P. J. Day

digging through the current PCI code and Kconfig files and it seems
like some of that could be made simpler, but i'm willing to be convinced otherwise.

I'm sure it could be cleaned up, and it would be great if you did!

I don't know the reason why all the arches source drivers/pci/pcie/Kconfig directly; it seems like that should be done from drivers/pci/Kconfig.

Quoted 23 lines

first, from arch/x86/Kconfig, rather than simply sourcing the file
"drivers/pci/Kconfig" (as is done with many other drivers directories), that Kconfig file defines:

menu "Bus options (PCI etc.)"

config PCI
bool "PCI support"
default y
... snip ...

and later on, sources the Kconfig files for PCI and PCIe individually:

source "drivers/pci/pcie/Kconfig"

source "drivers/pci/Kconfig"

and even further down, finally sources the file for PCI hotplug after PCMCIA:

source "drivers/pcmcia/Kconfig"

source "drivers/pci/hotplug/Kconfig"

I don't know all the history behind what we have now, so I can't give you much advice. I think you just have to work through the process of simplifying things and see whether it turns out to be feasible.

Quoted 6 lines · Bjorn Helgaas

Quoted 4 lines · Robert P. J. Day

digging through the current PCI code and Kconfig files and it seems
like some of that could be made simpler, but i'm willing to be convinced otherwise.

Quoted 29 lines

I'm sure it could be cleaned up, and it would be great if you did!

I don't know the reason why all the arches source drivers/pci/pcie/Kconfig directly; it seems like that should be done from drivers/pci/Kconfig.

Quoted 23 lines

first, from arch/x86/Kconfig, rather than simply sourcing the file
"drivers/pci/Kconfig" (as is done with many other drivers directories), that Kconfig file defines:

menu "Bus options (PCI etc.)"

config PCI
bool "PCI support"
default y
... snip ...

and later on, sources the Kconfig files for PCI and PCIe individually:

source "drivers/pci/pcie/Kconfig"

source "drivers/pci/Kconfig"

and even further down, finally sources the file for PCI hotplug after PCMCIA:

source "drivers/pcmcia/Kconfig"

source "drivers/pci/hotplug/Kconfig"

   ... snip ...

Quoted 4 lines

I don't know all the history behind what we have now, so I can't give you much advice. I think you just have to work through the process of simplifying things and see whether it turns out to be feasible.

one of the quirky features of the current Kconfig layout is that, in
some arch Kconfig files, the main PCI content is included, then pcmcia, *then* PCI hotplug, which means that when you pop into something like "make menuconfig" and wander over to the PCI menu, you see the majority of PCI selections, then the selection for PCCard, and *then* the choice for PCI hotplug, which strikes me as just, well, odd and confusing since, if you deselect PCI entirely, almost everything goes away except for (you guessed it) PCCard. (and that framebuffer selection as well.)

as you say, there may be some historical inertia as to why things
were done this way, but is there any *technical* reason why everything PCI-related can't just hang off of the drivers/pci/ directory via a single "source" directive?