lkml.org 
[lkml]   [2008]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: post 2.6.26 requires pciehp_slot_with_bus
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




\
 
 \ /
  Last update: 2008-07-30 04:55    [W:0.074 / U:0.436 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site