Jesse Barnes wrote: > On Monday, July 28, 2008 7:43 pm Kenji Kaneshige wrote: >>> Your systems don't have _RMV methods for the hotpluggable PCIe slots in >>> the DSDT? That's a shame; the Windows docs I found on PCIe hotplug >>> seemed to indicate that _RMV and _OSC (under Vista) were used to detect >>> whether a given slot was hot pluggable (I just googled for "windows pcie >>> hotplug" or something) so I was hoping that would be a reliable method... >>> Any other ideas? I'll go see if I can dig up some ExpressCard info. >> My systems don't have _RMV methods for the hot pluggable PCIe slots in the >> DSDT, but I don't think that's a shame. I suppose that the document you are >> referring describes how Windows handles ExpressCard slots. In my >> understanding, Hot Plug Surprise bit in the Slot Capabilities register is >> set to 1b on ExpressCard slots, and I believe that ACPI _RVM method is for >> the device that only supports surprise-style removal. I think this is why >> your system implements _RMV method for slots. > > Yeah, that may be. The document wasn't very clear; I was hoping that > something simple would be available. > >> On the other hand, hot pluggable slots on my servers are *not* ExpressCard >> slots, and all of them have Power Controller instead of surprise-style >> removal (Hot Plug Surprise bit in the Slot Capabilities register is set to >> 0b). So I believe there is no reason to implement _RMV methods for the hot >> pluggable PCIe slots on my systems. >> >> Here is an idea. How about using _RMV method to determine whether a given >> slot is actually hot pluggable when Hot Plug Surprise bit in the Slot >> Capabilities register is set to 1b on the slot? This is based on a little >> rough assumption that all PCIe slots that support surprise-style removal >> have _RMV method, though. Does this work for you? > > It's worth a try. We need *some* sort of better method to detect hot > pluggable slots... OK. I'll try to make a patch. According to PCI Express and PCI firmware spec, I think Hot Plug Capable bit in the Slot Capabilities register and ACPI _OSC are enough to detect hot pluggable slots. But I might be missing something especially about ExpressCard, or BIOS is just broken... Thanks, Kenji Kaneshige -- 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
