The failure mode is that after a PCI RST_n assertion, occasionally, depending on the clock phases, the PCI writes to PLB devices are terminated and the PCI device issues retry forever, until either the PCI or PLB reset is asserted. Note that PCI reads of PLB devices are functional.
This may occur 1 in 40 reset tries; the low probability of the failure does not suggest that it will happen in two sequential resets.
You can download the latest patch from:
http://www.xilinx.com/txpatches/pub/applications/misc/llink_wr_backend_async2.zip
- Please copy the "plbv46_master_v1_03_a" from the EDK build 'pcores' repository to your project local "pcores".
- Unzip and replace the "llink_wr_backend_async2.vhd" file in the your local "pcore" directory (i.e. under 'plbv46_master_v1_03_a\hdl\vhdl') with this latest file.
This issue is scheduled to be fixed in the "plbv46_master v1.04.a" and it will be included in the next version of the pci core.