SPRUJB3 March 2024 AM67 , AM67A , TDA4AEN-Q1 , TDA4VEN-Q1
As per PCIe Base Specifications, Root Complex ports only receive interrupts. There is no mechanism to generate interrupts from RC port to EP mode as per PCIe specification.
However, PCIe subsystem does support generation of interrupts from RC to EP. The downstream interrupts described in Section 12.2.1.3.4.3.1, PCIe Core Downstream Interrupts provides a mechanism for the RC to generate software triggered interrupts to the EP.