We have a DELL R230 server with Intel Chipset C236 and BIOS version 1.3.2.
This unit BIOS can't properly initialize PCIe devices based on "PLX PEX811x PCIe-to-PCI bridge".
Looks like it's an old issue that was solved in past for C602J, C610, C612 and X99 Chipsets. Also I don't have this problem on other DELL servers like: R220, R210, R200, R710, R430, R610 and PowerEdge 2950.
The issue occurs when the BIOS is configuring the Platform Controller Hub (PCH) based on the device capabilities. The affected cards are based on a PLX PEX811x PCIe-to-PCI bridge, which reports a set of capabilities and settings from its PCI Configuration Space to the BIOS.
However, it seems that the BIOS does not correctly interpret these values, as it first tries to write to an incorrect PCIe configuration register address and thereafter sets the maximum payload size in the PCH incorrectly.
The first fault causes the bridge to disable its PCI side, while the second fault causes the bridge to report fatal (non-resolvable) errors and to corrupt the data during transfer. The fact that this is caused by a bug in the BIOS has been confirmed by several sources.
Looks like only a BIOS update can solve this...