* Rostyslav Khudolii <ros@xxxxxxxx> wrote: > > My understanding, based on the above info, is that ACPI should be > > used. The direct register enablement is still possible for > > backwards compatibility, if needed. > > > > I think your observation proves a good point. The registers were > > moved starting in Zen. But this is not an issue on modern OSes > > since ACPI is used by default. > > This is my understanding too. However, what is the desired behavior > on Zen if the CONFIG_ACPI_MCFG and CONFIG_PCI_MMCONFIG are both > disabled? ECS should not be possible since the registers were moved, > right? If that's the case then, at the very least, it would be great > to have a warning message. > > > For your specific issue, I think we should determine if there is a > > configuration or a firmware problem. > > To give a bit more context: I am porting the kernel which works on > the AMD Ryzen™ Embedded V1000-based device. On that system, it seems > like the firmware doesn't disable IO access to ECS (which is wrong), > hence we have never experienced this issue before. Now, the > R2000-based device's firmware disables IO access to ECS (correctly) > and that's when the issue starts to happen. [ Sorry about the late reply. ] So what is the practical impact here? Do things start breaking unexpectedly if CONFIG_ACPI_MCFG and CONFIG_PCI_MMCONFIG are disabled? Then I'd suggest fixing that in the Kconfig space, either by adding a dependency on ACPI_MCFG && PCI_MMCONFIG, or by selecting those must-have pieces of infrastructure. Thanks, Ingo
