Re: [LinuxBIOS] More MCP55 hacking

[Lu, Yinghai]

You need to use 64 bit kernel if you enable pref64 in LinuxBIOS.

YH

-----Original Message-----
From: linuxbios-bounces+yinghai.lu=[e-mail]
[mailto:linuxbios-bounces+yinghai.lu=[e-mail]] On Behalf Of
Ed Swierk
Sent: Tuesday, December 12, 2006 4:37 PM
To: LinuxBIOS
Subject: Re: [LinuxBIOS] More MCP55 hacking

On 12/12/06, Lu, Yinghai  wrote:
> If still has problem
>
> #make the SB HT chain on bus 0, default is not (0)
> #default SB_HT_CHAIN_ON_BUS0=1
> 2.
> Power off your target for a while. You may drive it nuts.

The patch didn't help, but commenting out SB_HT_CHAIN_ON_BUS0 did. Now
the SB is on bus 1 and the devices are getting initialized only once.

Any idea what those "Unable to handle 64-bit address space for bridge
0000:01:03.0" errors are about? The stuff about IO/MEM/PREFETCH
windows being disabled doesn't look good either.

I suppose the first order of business is to get interrupts going,
though.

--Ed

[LinuxBIOS] More MCP55 hacking

[Ed Swierk]

On 12/12/06, Lu, Yinghai  wrote:
> You need to use 64 bit kernel if you enable pref64 in LinuxBIOS.

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.

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

--Ed

[LinuxBIOS] More MCP55 hacking

[Segher Boessenkool]

> 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.

Segher