Re: [PATCH] x86/pci: try to detect host_bridge pci_cfg_space

H. Peter Anvin
2009-03-07T01:05:26Z

H. Peter Anvin wrote:
> Yinghai Lu wrote:
>> Impact: get correct pci_cfg_size for host_bridge
>>
>> more host bridges support 4k cfg, so check them directly
>> instead of quirks.
>>
>> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
>
> I'm utterly confused by this. This is basically saying we should try to
> probe for an extended device space for every host bridge. Logically
> speaking, this is valid: if there is a valid path by which we can probe
> for byte 256 then it should succeed.
>
> HOWEVER, the same argument applies for *every single device*. So if
> this does indeed work, why should we limit it to host bridges?
>

Looking at the code (as opposed to just the patch) made it a bit
clearer. The argument you're making here is that only host bridges are
known to have extended address space without also having a PCI-X
extension header, right?

-hpa