Critical Issue
Description
Stratix V GX Hard IP for PCI Express variants using CvP and x2 configuration fail during link training initialization.
Resolution
The workaround is to specify a x4 configuration and let the link downtrain to x2. CvP updates work reliably using this workaround starting with release 12.0 of the Quartus II software. This issue will be fixed in a future version of the Quartus II software.