On Tue, Apr 14, 2015 at 8:03 PM, Rafael J. Wysocki <r...@rjwysocki.net> wrote: > On Tuesday, April 14, 2015 12:28:12 PM Henrique de Moraes Holschuh wrote: >> On Mon, Apr 13, 2015, at 11:23, Rafael J. Wysocki wrote: >> > From: Rafael J. Wysocki <rafael.j.wyso...@intel.com> >> > >> > Refine the mechanism introduced by commit f244d8b623da (ACPIPHP / radeon >> > / nouveau: Fix VGA switcheroo problem related to hotplug) to propagate >> > the ignore_hotplug setting of the device to its parent bridge in case >> > hotplug notifications related to the graphics adapter switching are >> > given for the bridge rather than for the device itself (the need to >> > be ignored in both cases). >> >> I do apologise if this is a stupid question, but is there any chance the >> bridge will be connected to other devices that do require hotplug handling, >> and not just to the GPU? > > The bridge is actually a downstream PCIe port holding the GPU, so no. :-)
When radeon/nouveau call pci_ignore_hotplug(), that's the case, but in general all we know is that pci_ignore_hotplug() receives a PCI device. We don't know whether it's PCI or PCIe. In the hotplug topologies I'm familiar with, a bridge only leads to one hot-pluggable slot, but I don't remember anything that would guarantee that. For PCIe, I think there can only be one slot, but for PCI I would think it possible to have one bridge leading to several hotpluggable slots, with the hotplug controller(s) being separate from the bridge. Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
