Re: Forced PCI support in kernel

[Geert U. <Gee...@so...>]

On Tue, 6 Jun 2000, Michel [iso-8859-1] Dänzer wrote:
> Geert Uytterhoeven wrote:
> > > > As I said, PCI support is currently not a configure option but depends
> > > > on the architecture. If you want to change that, go ahead. I don't think
> > > > moving even further from the 'official' kernel is a good idea though.
> > 
> > Some archs do have CONFIG_PCI questions, though. Just like we have a
> > CONFIG_ZORRO question.
> 
> Well, no problem then :)
> 
> > > What difference are there if you enable PCI or not ?
> > > 
> > > will enabling PCI on all apus kernel be causing a problem ? making the
> > > kernel bigger ?
> > 
> > It will make the kernel bigger.
> 
> Can you give an estimate how much?

callisto$ ls -l drivers/pci/*[.oa]
-rw-r--r--    1 geert    users        2792 Jun  5 21:52 drivers/pci/compat.o
-rw-r--r--    1 geert    users      358400 Jun  5 21:52 drivers/pci/names.o
-rw-r--r--    1 geert    users      405592 Jun  5 21:52 drivers/pci/pci.a
-rw-r--r--    1 geert    users       18528 Jun  5 21:52 drivers/pci/pci.o
-rw-r--r--    1 geert    users       29549 Jun  5 21:52 drivers/pci/pci_core.o
-rw-r--r--    1 geert    users        8380 Jun  5 21:52 drivers/pci/proc.o
-r--r--r--    1 geert    users        8213 Jun  5 21:35 drivers/pci/quirks.c
-rw-r--r--    1 geert    users        4824 Jun  5 21:52 drivers/pci/quirks.o
-rw-r--r--    1 geert    users        2480 Jun  5 21:52 drivers/pci/setup-bus.o
-rw-r--r--    1 geert    users        1692 Jun  5 21:52 drivers/pci/setup-irq.o
-rw-r--r--    1 geert    users        3272 Jun  5 21:52 drivers/pci/setup-res.o
-rw-r--r--    1 geert    users        3416 Jun  5 21:52 drivers/pci/syscall.o

Notes:
  - I compiled with debugging on
  - The name database will be freed after booting (you can also disable it
    completely with CONFIG_PCI_NAMES=n)

After using objdump and summing up, I get about 113 KB of initdata (freed
afterwards) and 18 KB permanent (plus a bit for data structures that are
kmalloc'ed).

Not that bad for a nice /proc/bus/pci interface, right? :-)

> > > If the kernel is pci less, just don't propose pm2fb ?
> > >
> > > I suppose this would be no more changes than adding a configure option to
> > > the configuration stuff ?
> > 
> > Just remove the test for CONFIG_AMIGA. People need to be not so stupid to
> > disable CONFIG_ZORRO if they want to use Zorro devices also, so this sounds
> > OK to me.
> 
> What about automatically enabling PCI if the user wants pm2fb? Otherwise, we
> will have people ask "Why has pm2fb disappeared?" :)

That's much more difficult, since CONFIG_PCI must be y before you can see the
pm2fb question. Besides, my argument was that you must say CONFIG_ZORRO=y as
well if you want to use Zorro graphics cards. So let's put in the FAQ that the
pm2 is a PCI video card (technically it is).

Gr{oetje,eeting}s,

						Geert

--
Geert Uytterhoeven ------------- Sony Software Development Center Europe (SDCE)
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