On Thu, 2 Oct 2008 19:17:33 +0400 Anton Vorontsov avorontsov@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@ru.mvista.com
applied to mpc83xx/next.
Thanks,
Kim