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BIOS issue affecting operation of certain DekTec PCIe cards  

BIOS issue affecting operation of certain DekTec PCIe cards

Due to an issue in Intel's BIOS reference code for their C602J, C610, C612 and X99 chipsets, some DekTec PCIe cards are recognized but cannot stream any data.
The problem can be solved in most cases by upgrading to the latest BIOS


Affected DekTec Products

These DekTec cards contain a PLX PEX811x PCIe-to-PCI bridge chip that is not properly initialized by some BIOS versions.

Known Affected Systems

System Fix?
HP ProLiant Gen9 BIOS v1.40
Bug is re-introduced
in BIOS v1.50
and later
HP Z440, Z640, Z840 Aug/Sept 2015
Supermicro servers BIOS versions
released in 2015
Supermicro X10 series

If a BIOS fix is available, upgrade the BIOS on your system and DekTec cards will operate normally again.

It is likely that other systems with Intel C610, C612 or X99 chipset will be affected, too.

Please let us know if you encounter any other having the described issue with DekTec cards.

Problem Description

Due to an issue in Intel's BIOS reference code for their C602J, C610, C612 and X99 (formerly Wellsburg) chipsets, servers and workstations from several vendors may have severe issues running some DekTec cards (see left column).

The PC system will boot normally and the DekTec card will be detected by the DekTec driver and DtInfo application. DekTec applications will also start normally. However, when trying to play out or record a stream, nothing happens: The card does not generate or capture data and the application does not report any progress.

Problem Resolution

As this issue is caused by the system BIOS, it has to be fixed by the system vendor (new BIOS version).

It is not possible to resolve the issue via a firmware upgrade for the DekTec card.

The system vendors have been informed of this issue and they are either working on a solution of have already fixed it in the form of a BIOS update. In the table on the left side we maintain a list of known affected systems and whether a BIOS version fixing the issue is available.

Detailed Analysis

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.

Please feel free to contact DekTec in case you have any questions regarding this issue.