Re: [Patch 1/1] x86 pci: Add option to not assign BAR's if not already assigned

[Mike Travis <travis@sgi.com>]

H. Peter Anvin wrote:
> On 05/28/2010 10:10 AM, Mike Travis wrote:
>>
>> H. Peter Anvin wrote:
>>> On 05/28/2010 09:53 AM, Mike Travis wrote:
>>>> Any further consideration for this patch, or has it been rejected?
>>> Well, it's really up to Jesse, but as far as I can see, this patch is a
>>> net loss of functionality and doesn't actually add anything.  Without
>>> this patch, some resources that were not assigned by BIOS will be
>>> unreachable.  With this patch, *all* resources that were not assigned by
>>> BIOS will be unreachable...
>>>
>>> 	-hpa
>>>
>> Apparently you're missing the point of the patch?  The patch is needed
>> because BIOS is purposely not assigning I/O BAR's to devices that won't
>> use them, freeing up the resource for devices that do need them.  Where
>> is the "all" resources that are not reachable?
>>
> 
> No, the patch isn't needed for those.
> 
> Without your patch:
> 
> - Devices assigned by BIOS remain assigned;
> - Devices not assigned by BIOS get assigned until address space
>   exhausted.
> 
> With your patch:
> 
> - Devices assigned by BIOS remain assigned;
> - Devices not assigned by BIOS never get assigned at all.
> 
> What am I missing here?
> 
> 	-hpa
> 

BIOS still assigns the MMIO BAR's so the devices are alive.