FDDI May Hang During Heavy Load (BugIDs 4485758, 4174861, 4486543)

The PCI FDDI card has known hardware problems related to DTXSUSP (DMA TX process suspend interrupt) and DRXSUSP (DMA RX process suspend interrupt) bits in the MAIN_CONTROL and MAIN_STATUS registers. These hardware bugs minimally affect FDDI functionality under normal conditions. However, under a very heavy TX or RX load, the card posts an unexpected interrupt. The system posts the error message, "Interrupt level 6 is not serviced". After 20 such errors, the pcipsy driver shuts down interrupt processing for the FDDI and hangs FDDI.