[LinuxBIOS] More MCP55 hacking

Segher Boessenkool segher at kernel.crashing.org
Wed Dec 13 17:14:54 CET 2006

> CONFIG_PCI_64BIT_PREF_MEM is 0, so it's not clear to me why Linux is
> seeing the PCI_PREF_RANGE_TYPE_64 bit set in the configuration
> registers of those bridges.

Because it's a hardware property.

The error means a single bar needed 4GB or more of address
space, btw.  Sounds like something is wrong :-)

> Perhaps the pref64 bit is set by default by the hardware; if so, is
> there a way to clear it in LinuxBIOS?

No. BARs are 64-bit or not, there's no way to change that.
It doesn't matter however; if the top half of a 64-bit BAR
is set to zeroes, it works fine on a 32-bit system.


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