The following evaluation was done in early May ....
In summary, EDR is brand new in upstream kernels and to my knowledge has not been exercised in-house at Canonical, and may be difficult to test due to a lack of systems with EDR functionality in their firmware. I am unsure as to what the state of regression testing is with regards to this type of PCI functionality. Some followup patches and discussion after the original EDR submission are below. To be clear, these are not part of the request from Nvidia. These are upstream followups to the EDR patch set, and are indicative of the final state of this functionality still being in flux. https://lore.kernel.org/linux-pci/1588272369-2145-1-git-send-email-jonathan.derr...@intel.com/ The above is unapplied upstream; it is proposed to fix an issue with the negotiation between the operating system and firmware for control for DPC, and as of 1 May 2020 is pending waiting for https://lore.kernel.org/linux-pci/67af2931705bed9a588b5a39d369cb70b9942190.1587925636.git.sathyanarayanan.kuppusw...@linux.intel.com/ to be sorted out. This patch (which is applied upstream to pci git tree for merging in 5.8) relates to how the operating system and firmware negotiate control of AER and DPC via the "firmware first" bit in the ACPI HEST vs. using the _OSC ACPI method. Prior to this patch, the ACPI HEST takes priority; after this patch, _OSC is the only method consulted. This second patch could: (a) affect Nvidia's use of DPC / EDR, depending upon how their firmware is negotiating the control with the operating system, and (b) affect our existing installed base platforms that currently end up negotiating one way, but end up with a different result under this patch. E.g., the platform advertises "firmware first" in the ACPI HEST, but not via _OSC. I think it is more likely that server class systems will already do this correctly, and that embedded / "IoT" type devices are more likely to see an impact from this change. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1885030 Title: [Intel] Add Error Disconnect Recover support To manage notifications about this bug go to: https://bugs.launchpad.net/intel/+bug/1885030/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs