[U-Boot] [PATCH] mpc83xx: fix PCI scan hang on the standalone MPC837xE-MDS boards

[Kim Phillips]

On Thu, 2 Oct 2008 19:17:33 +0400
Anton Vorontsov <avorontsov at ru.mvista.com> wrote:

> The MPC837xE-MDS board's CPLD can auto-detect if the board is on the PIB,
> standalone or acting as a PCI agent. User's Guide says:
> 
> - When the CPLD recognizes its location on the PIB it automatically
>   configures RCW to the PCI Host.
> - If the CPLD fails to recognize its location then it is automatically
>   configured as an Agent and the PCI is configured to an external arbiter.
> 
> This sounds good. Though in the standalone setup the CPLD sets PCI_HOST
> flag (it's ok, we can't act as PCI agents since we receive CLKIN, not
> PCICLK), but the CPLD doesn't set the ARBITER_ENABLE flag, and without
> any arbiter bad things will happen (here the board hangs during any config
> space reads).
> 
> In this situation we must disable the PCI. And in case of anybody really
> want to use an external arbiter, we provide "pci_external_aribter"
> environment variable.
> 
> Signed-off-by: Anton Vorontsov <avorontsov at ru.mvista.com>

applied to mpc83xx/next.

Thanks,

Kim