On Wed, Apr 13, 2016 at 11:08:37AM +0200, Andreas Noever wrote: > > <- Now, my understanding is that Macs do not use ACPI hotplug but > > instead this is all native, correct? When you have the controller > > exposed all the time, of course you can get hotplug events and handle > > them in the driver. > > > > However, problem arises when enumeration and configuration is actually > > done in BIOS SMI handler, like in normal non-Mac PCs. If the port is in > > D3 the handler is not smart enough to move it back to D0 and then > > re-enumerate ports. It just gives up. > Is this issue specific to the "ACPI/SMI Thunderbolt" implementations > used in non-Mac PCs or is PCI hotplug in general done through SMI/ACPI > instead of the native pciehp port driver? Wouldn't it make more sense > to only disable runtime suspend on non-Mac thunderbolt ports (or ports > using ACPI hotplug, if that is detectable). I think it is specific to ACPI hotplug implementations (non-Mac PCs). We should be able to detect which one is used. ACPI _OSC method is used to allow/disallow native PCIe hotplug so I think we use that information along with the slot capabilities to decide whether we enable or disable runtime PM. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
