Re: post 2.6.26 requires pciehp_slot_with_bus

[Jesse Barnes <jbarnes@virtuousgeek.org>]

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...

Thanks,
Jesse