correct way for handling PCIe in endpoint mode

correct way for handling PCIe in endpoint mode

[Scott Coulter]

Hi all,

Maybe a silly questions, but what is the suggested way for handling a
processor which has a PCIe interface, but the interface is not
configured to be the root complex (endpoint only)?

Should the PCIe interface appear in the dts?  If so, with what
parameters?

Should the kernel config contain CONFIG_PCI, etc. ?

Thanks,
Scott




___________________________________________________________________

  Scott N. Coulter
  Senior Software Engineer
 =20
  Cyclone Microsystems         =20
  370 James Street              Phone:  203.786.5536 ext. 118
  New Haven, CT 06513-3051      Email:  scott.coulter@cyclone.com
  U.S.A.                        Web:    http://www.cyclone.com
___________________________________________________________________

Re: correct way for handling PCIe in endpoint mode

[Ira Snyder]

On Tue, Feb 10, 2009 at 07:39:47AM -0500, Scott Coulter wrote:
> 
> Hi all,
> 
> Maybe a silly questions, but what is the suggested way for handling a
> processor which has a PCIe interface, but the interface is not
> configured to be the root complex (endpoint only)?
> 
> Should the PCIe interface appear in the dts?  If so, with what
> parameters?
> 
> Should the kernel config contain CONFIG_PCI, etc. ?
> 

I'm in a similar situation, except I'm using PCI instead of PCIe. I've
tried both removing the PCI interface from the dts, and disabling
CONFIG_PCI. Both work fine.

You probably don't want to leave the PCI interface in the dts and also
leave CONFIG_PCI enabled. I ran into some really strange issues this
way... (Linux ran through the quirks and tried to re-initialize a
network card, even though the driver was disabled, etc.)

I think the suggested way is to remove the PCI interface from the dts,
that way you can potentially share a kernel between similar boards with
and without PCI root interfaces, just by changing the dts.

Ira