Why does the Linux re-scan fail when the Class Code of the Intel® Arria® 10, Intel® Cyclone® 10 and Intel® Stratix® 10 Hard IP for PCI Express* is configured as all zero ?

Due to the Class Code = 0x00 is for the device which is built before the Class Code definitions were finalized , the Linux re-scan might fail when the Class Code of the Hard IP for PCIe Express* is configured as all zero.  This re-scan failure might cause system memory assignment issues, for example, the BAR of FPGA can not be programmed correctly.

To work around this problem , please refer to the Class Code definitions in the PCI Express* Base Specification to change the Class Code to non-zero value.

Starting with the Intel® Quartus® Prime Pro edition software version 19.3 the class code will default to 0xFF to prevent the above system failure, however the correct Classs Code definition should still be set by the user..