Does anyone know now to hotplug PCIe devices with PCIe switches. By this I mean a PCIe card with a PCIe switch. Having a single upstream port for the host PC, and and multiple downstream ports for Multiple PCIe devices. Here is an example of such a card in the consumer PC space:

https://www.google.com/search?q=asus...ed=0CAcQ_AUoAg

I have tried to hotplug such PCIe devices with kernels from 2.6.34 to 3.19. The earlier kernels panic, the more recent kernels only give one downstream PCIe bus and device. I would like to be able to hotplug and get all of the downstream
buses and devices.

Thanks

Typically it is up to the manufacturer to provide driver support of special devices that do things like port multiplying. That is the case with my SATA port multiplier. It is worth looking up the latest Linux device drivers for your hardware with the vendor. In many cases the vendor provided drivers are binary blobs.

This is fixed, the trick was to renumber the PCIe buses such that when the switch is hot-pluged, there is sufficient bus-number space for the insert. The function pci_scan_bridge() should be updated to allocate bus-numbers is a tunable sparce space when in pcibios_assign_all_busses mode. So there is a kernel incomplete feature here.

1 members found this post helpful.

You may want to file a bug report with the kernel maintainer that manages that subsystem. This way they can have it on a backlog todo or a contributor could pipe up with a patch.