On 7/29/05, Rajesh Shah <[EMAIL PROTECTED]> wrote: > On Thu, Jul 28, 2005 at 07:45:49PM +0900, Rajat Jain wrote: > > > > Okay. I'm sorry but I'm not very clear with this. I'm just putting > > down here my understanding. So basically we have two mutually > > EXCLUSIVE hotplug drivers I can use for PCI Express: > > > A hotplug slot can be controlled only by a single hotplug > technology - pcie shpc or acpiphp. However, different parts of > the I/O hierarchy can be controlled by different technologies. > For example, a host bridge I/O complex can be hotplugged using > acpiphp, but end devices under this IO complex may be hotpplugged > using pcie or shpc hotplug. > > > 1) "pciehp.ko" : We use this PCIE HP driver when our BIOS supports > > Native Hot-plug for PCI Express (which means that hot-plug will be > > handled by OS single handedly). > > > > 2) "acpiphp.ko" : We use this "generic" ACPI HP driver when BIOS > > allows only ITSELF to handle hot-plug events. > > > No, acpi hotplug is not handled by BIOS only. > Both acpi and pcie hotplug need firmware support as well as hardware > support. Hardware in many (but not all) systems support both types of > hotplug and its up to the BIOS to decide which type to support. If the > platform supports pcie hotplug, you see an _OSC & _SUN methods in the > ACPI namespace and the pciehp driver controls hotplug slots. If the > system supports acpi hotplug, you see _ADR and _EJ0 methods in the ACPI > namespace and the acpiphp driver controls the corresponding hotplug slots. > > Rajesh >
Thanks a lot. It has proved to be a very useful information for me. I can now do some R&D on it. Thanks again, Rajat - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
