PRIME DRI2 Offloading Pulled Into X.Org Server

[curaga]

At least some pcie must support hotplug, else how do you explain thunderbolt? (pci-e via a different cable, hotpluggable)

[liam]

At least some pcie must support hotplug, else how do you explain thunderbolt? (pci-e via a different cable, hotpluggable)

My guess is that thunderbolt employs a dummy device. When you attach something, the dummy device just appears to move from a low power state to an active state.

[Serafean]

from http://electronicdesign.com/products...ra-of-ras35149 :

PCI Express, since its inception, was designed to comprehend hot-plug functionality. As such, hot-plug registers are part of PCIe's capabilities, providing the operating system with a standard hot-plug hardware register interface accessible through configuration access on the PCIe bus. PCI Express also defines a standard usage model by defining the hot-plug capabilities required of hardware at a base architectural level. The native support for hot-plug control enables innovative server module form factors to be inserted or removed under power without requiring that the chassis be opened.

In a PCIe-based server system, hot-plug slots may be sourced either from the chipset or the downstream ports of a switch. As PCIe is a point-to-point bus, switches are usually required for slot expansion and creation because of the limited number of ports of the root complex. These switches appear to the software as PCI-to-PCI bridges, and each port implementing a slot that is hot-plug capable will contain its own set of hot-plug registers in the bridge configuration space. These registers report the presence or absence of defined hot-plug mechanisms to software. They contain control for power as well as indicators on the slot, along with notification of card insertion/removal, latch open/close and of the attention button press. The software is notified by sending an interrupt upstream to the root complex. The notification option is implementation-dependant.

From this I deduce that PCIe hotplugging is possible.
However, when dealing with switchable graphics, for which I think that VGA_Switcheroo is enough. Riht now I don't see a model when a GPU would be hotplugged.

[liam]

from http://electronicdesign.com/products...ra-of-ras35149 : From this I deduce that PCIe hotplugging is possible.
However, when dealing with switchable graphics, for which I think that VGA_Switcheroo is enough. Riht now I don't see a model when a GPU would be hotplugged.

And that's what I get for referencing wikipedia.
Thanks for the reference, and I stand corrected.