AR# 45847: Kintex-7 FPGA KC705 Base TRD - Driver does not unload successfully
Kintex-7 FPGA KC705 Base TRD - Driver does not unload successfully
The Kintex-7 FPGA KC705 Base TRD driver does not unload successfully? How can this be fixed?
On some Intel x58 chipsets, the KC705 Base TRD driver does not unload successfully (driver module xdma_k7 is not removed) and causes the system to crash. This is believed to be due to intel-iommu having issuesfreeing up DMA page tables.
UG882 details two ways to remove the driver: i. Using thek7_trd_lin_quickstart script, which removes the driver when the Peformance Monitor is closed. ii. Using the make remove command (Appendix D of UG882).
This issue can be resolved as follows: When Fedora 16 Live is booting i. Press tab for full configuration options on menu items. ii. Add iommu=pt64 at the end of the line vmlinuz0 initrd=initrd0 ...rd.md=0 rd.dm=0 iii. Hit the enter key to boot with this option.