UEFI lesson to get Current Link Speed for PCI devices.

[ayushdas2000]

Hi Kostr. Been Learning Uefi development from these lessons. I am trying to write a uefi application to get Current Link speed for pci devices right now but havent been able to reach a working code. Would appreciate any leads or a lesson for the same. Thanks

[Kostr]

Hi @ayushdas2000. There is a lesson about reading PCIe configuration space Lesson_30. You just need to understand how to find current link speed from the PCIe configuration space.
Basically you need to search for the necessary capability starting from the Capability Pointer register. And then read Current Link speed from that capability. Consult the PCIe specification or lspci sources for the implementation details.

You can also grab the configuration space parsing logic from my pcie-mdr application developed for the openbmc.

[ayushdas2000]

Thanks a lot. Will try this

[ayushdas2000]

Was able to get this done. Thanks a lot