On Wed, Aug 30, 2023 at 02:37:07PM +0530, Thippeswamy Havalige wrote: > Add support for Xilinx XDMA Soft IP core as Root Port. > > The Zynq UltraScale+ MPSoCs devices support XDMA soft IP module in > programmable logic. > > The integrated XDMA soft IP block has integrated bridge function that > can act as PCIe Root Port. > + if (!pci_is_root_bus(bus)) { > + /* Checking whether the link is up is the last line of > + * defense, and this check is inherently racy by definition. > + * Sending a PIO request to a downstream device when the link is > + * down causes an unrecoverable error, and a reset of the entire > + * PCIe controller will be needed. We can reduce the likelihood > + * of that unrecoverable error by checking whether the link is > + * up, but we can't completely prevent it because the link may > + * go down between the link-up check and the PIO request. > + */ Looks fine to me. If Lorenzo or Krzysztof thinks this is ready to go, maybe they will tidy the comment above, i.e., /* * Checking whether ...