Disable PCI while CONFIG_PCI=y

Disable PCI while CONFIG_PCI=y

[Xianghua Xiao]

Is it possible to do something like 'pci=off' to have the same effect
as turning of CONFIG_PCI during menuconfig?
I want to build one image for both PCIE RC and PCIE EP(endpoint), for
EP I do not need PCI to be enabled at all.

looking at drivers/pci/pci.c I don't see such option exists, am I
missing something?

Thanks,
Xianghua

Re: Disable PCI while CONFIG_PCI=y

[Randy Dunlap]

On Wed, 13 Apr 2011 15:05:59 -0500 Xianghua Xiao wrote:

> Is it possible to do something like 'pci=off' to have the same effect
> as turning of CONFIG_PCI during menuconfig?
> I want to build one image for both PCIE RC and PCIE EP(endpoint), for
> EP I do not need PCI to be enabled at all.
> 
> looking at drivers/pci/pci.c I don't see such option exists, am I
> missing something?

Hm. Documentation/kernel-parameters.txt says:


	pci=option[,option...]	[PCI] various PCI subsystem options:
		earlydump	[X86] dump PCI config space before the kernel
			        changes anything
		off		[X86] don't probe for the PCI bus

What $ARCH are you using?

See arch/x86/pci/common.c::pcibios_setup() for code that handles
	pci=off

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: Disable PCI while CONFIG_PCI=y

[Xianghua Xiao]

Yes I read that but my ARCH is arm.

Thanks,

On Wed, Apr 13, 2011 at 3:10 PM, Randy Dunlap <rdunlap@xenotime.net> wrote:
> On Wed, 13 Apr 2011 15:05:59 -0500 Xianghua Xiao wrote:
>
>> Is it possible to do something like 'pci=off' to have the same effect
>> as turning of CONFIG_PCI during menuconfig?
>> I want to build one image for both PCIE RC and PCIE EP(endpoint), for
>> EP I do not need PCI to be enabled at all.
>>
>> looking at drivers/pci/pci.c I don't see such option exists, am I
>> missing something?
>
> Hm. Documentation/kernel-parameters.txt says:
>
>
>        pci=option[,option...]  [PCI] various PCI subsystem options:
>                earlydump       [X86] dump PCI config space before the kernel
>                                changes anything
>                off             [X86] don't probe for the PCI bus
>
> What $ARCH are you using?
>
> See arch/x86/pci/common.c::pcibios_setup() for code that handles
>        pci=off
>
> ---
> ~Randy
> *** Remember to use Documentation/SubmitChecklist when testing your code ***
>

Re: Disable PCI while CONFIG_PCI=y

[Randy Dunlap]

On Wed, 13 Apr 2011 17:01:38 -0500 Xianghua Xiao wrote:

> Yes I read that but my ARCH is arm.
> 

It would probably make sense to implement
	pci=off
for any $arch.

Any problem with that, linux-pci??


> 
> On Wed, Apr 13, 2011 at 3:10 PM, Randy Dunlap <rdunlap@xenotime.net> wrote:
> > On Wed, 13 Apr 2011 15:05:59 -0500 Xianghua Xiao wrote:
> >
> >> Is it possible to do something like 'pci=off' to have the same effect
> >> as turning of CONFIG_PCI during menuconfig?
> >> I want to build one image for both PCIE RC and PCIE EP(endpoint), for
> >> EP I do not need PCI to be enabled at all.
> >>
> >> looking at drivers/pci/pci.c I don't see such option exists, am I
> >> missing something?
> >
> > Hm. Documentation/kernel-parameters.txt says:
> >
> >
> >        pci=option[,option...]  [PCI] various PCI subsystem options:
> >                earlydump       [X86] dump PCI config space before the kernel
> >                                changes anything
> >                off             [X86] don't probe for the PCI bus
> >
> > What $ARCH are you using?
> >
> > See arch/x86/pci/common.c::pcibios_setup() for code that handles
> >        pci=off
> >
> > ---

---
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***

Re: Disable PCI while CONFIG_PCI=y

[Jesse Barnes]

On Wed, 13 Apr 2011 15:37:24 -0700
Randy Dunlap <rdunlap@xenotime.net> wrote:

> On Wed, 13 Apr 2011 17:01:38 -0500 Xianghua Xiao wrote:
> 
> > Yes I read that but my ARCH is arm.
> > 
> 
> It would probably make sense to implement
> 	pci=off
> for any $arch.
> 
> Any problem with that, linux-pci??
> 

Yeah I'm ok with it assuming the patch looks good and isn't too
invasive.  I'd think on EP devices you'd want a more pared down kernel
image (so CONFIG_PCI=n among many other things), but if you really want
to share binary images yeah we'll need a runtime check.

Jesse