Hi everyone,
I’m working with the Honeycomb LX2 system and wanted to confirm whether PCIe hot-plug is actually supported. The PCI capabilities module reports that hotplug capability is present, but I’ve seen errata for some Layerscape boards where the advertised hot-plug capability turned out to be incorrect or not fully supported.
Could anyone clarify whether PCIe hot plug is functional on Honeycomb LX2, and if there are any known limitations or errata I should be aware of?
Thanks,
To be clear, PCIe hotplug support is as much about the board design, and drivers as actual support it for it by the host controller. Generally host controller support for hotplugging requires support for a mechanical presence switch, which the layerscape does not. This would mean to full support hotplugging there would need to be driver plumbing that used an external GPIO and then forced a re-enumeration of the PCIe bus to probe the device. Of course you would also need a connector that is electrically safe to hot plug while running.
The advertised hotplug support is a default value of the host controller IP that is used, but our boards to not support this feature.