Re: Linux 2.6.27-rc5: System boot regression caused by commita2bd7274b47124d2fc4dfdb8c0591f545ba749dd

[Linus Torvalds]

On Sun, 31 Aug 2008, Yinghai Lu wrote:
> 
> wonder how the probe could find out the size of is 1fff_ffff..

Heh. That's how PCI sizing works: you write all ones to the register, and 
read back the result. The low bits won't change, and that indicates the 
size.

But if _none_ of the bits change, then that simply means that the size 
will be calculated to be 0xffffffff-start.

So the sizing will "work", it will just always report that the BAR covers 
everything from start to the 4G limit.

		Linus
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