[U-Boot-Users] What's the relationship between pci_init() and POST for PCI devices?

[U-Boot-Users] What's the relationship between pci_init() and POST for PCI devices?

[Birkin Shen]

Dear all:

My board is based on MPC8241.

I defined CONFIG_PCI_PNP to support PCI Bus by PNP.

Now I want to have POST function for devices on PCI Bus, but I'm not sure about whether the function pci_init() has done the POST work. 

I think the pci_init() hasn't done the POST work, am I right?

Birkin

[U-Boot-Users] What's the relationship between pci_init() and POST for PCI devices?

[Stephen Williams]

Birkin Shen birkin_shen-at-usish.com |u-boot-users| wrote:
> I defined CONFIG_PCI_PNP to support PCI Bus by PNP.
> 
> Now I want to have POST function for devices on PCI Bus, but I'm
> not sure about whether the function pci_init() has done the POST work.
> 
> I think the pci_init() hasn't done the POST work, am I right?

The CONFIG_PCI_PNP flag turns on u-boot doing a pci resource
allocation. This causes pci_init to scan the PCI bus and map all the
BARs and interrupts. That is all it means. Even without this config
defined, pci_init turns on the PCI bus for your processor.

In any case, I do not believe U-Boot (pci_init in particular) goes
through the PCI devices looking for BIST registers and running
self tests.

If you are booting Linux, it is not necessary to do the PNP part.
I leave it off on my PPC405GPr based board, and Linux does the
right thing.
-- 
Steve Williams                "The woods are lovely, dark and deep.
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