[coreboot] Issue with CIMX/SB800 PCIe Port Initialization

Marc Jones marcj303 at gmail.com
Mon Jan 16 20:22:59 CET 2012

On Mon, Jan 16, 2012 at 10:18 AM, Wolfgang Kamp - datakamp
<wmkamp at datakamp.de> wrote:
> Hello,
> I found a problem with the PCI enumeration of the PCIe Ports in the
> CIMX/SB800 Southbridge for the INAGUA platform.
> The …/southbridge/amd/cimx/sb800/late.c routine calls the function
> sb_Before_PCI_Init after
> case (0x16 >>3) | 2. This means when the PCI Express ports (0x15 <<3) | 0
> are probed in the routine ../devices/pci_device.c function
> pci_probe_dev they are not yet initialized. The probing fails and also
> devices behind the bridge are not recognized.
> Behind the PCIe bridge I have an Intel 82574 LAN chip.
> But if I move the call to sb_Before_PCI_Init behind case  (0x15 <<3) | 0 the
> enumeration succeed but coreboot crashes later into nothing. The Sage
> Debugger fails.
> I can’t imagine why.
> Marc have you any idea?

This looks like a problem in the sb800 cimx wrapper logic. Cimx
doesn't treat the devices separately. it lumps all the configuration
and enables together, making the coreboot chipset device enable
callback fail to enable the device, so it gets disabled. The sb900
wrapper appears to fix this issue with cimx setup in early init. You
may want to try porting those changes to the sb800.

I don't know why it fails later, but I assume it is due to the missing
config since you moved the call earlier in the process. You could try
calling it multiple times. I'm not sure how it handles that, though.

Do you have any comments?



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