Hi all, We have a PCIE card which has a PEX8732 switch on-board, and there are two endpoint SOCs like graphic decoder behind the switch, and by default the ACS is enabled in 8732. We use the p2p DMA to transfer data between these two endpoint SOCs, and if the host server is not enable ACS in BIOS, the p2p works well, but when ACS is enabled in BIOS, the p2p is always failed. With the help of a protocol analyzer, we can see that the TLP is redirected to RC, and RC just discard it. I tried to find how to make RC forward redirected TLP to its original target, but nothing found, it seems this is highly related to the RC vendors. In the PCIE 4.0 spec, the section of the RC behavior of the p2p request redirect said that ''implementation-specific logic within the RC that determines whether the request is directed towards its original target, or blocked as an ACS Violation error. the algorithms and specific controls for making this determination are not architected by this spec''. So is there some spec or document to describe how to set the RC? Any suggestion is appreciated. Regards, Eric
