Re: Linux 2.6.27-rc5: System boot regression caused by commit a2bd7274b47124d2fc4dfdb8c0591f545ba749dd

Linus Torvalds
2008-08-31T18:06:56Z

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