Hi Bjorn and Rafael, Our test found that if set pcie_aspm=off in cmdline, the AER and hotplug is also disabled without negotiating with firmware through _OSC. Driver regards ASPM as a requirement of PCIe support and if it's disabled, we'll not enable other advanced services like AER and hotplug at all. Any reason for binding ASPM with other PCIe services? There is an attempt to split ASPM with other services [1] but the patch is not accepted. The original patch [2] makes ASPM a necessity related a bugzilla report but I didn't figure out the detailed reason for doing so. Can we add some detailed reasons in the code why regards ASPM a necessity? or shall we split ASPM and other services as they are independent? [1] https://lore.kernel.org/linux-pci/20190702201318.GC128603@xxxxxxxxxx/ [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=415e12b23792 Thanks, Yicong