On Tue, Apr 13, 2010 at 12:35 AM, Arne Georg Gleditsch firstname.lastname@example.org wrote:
That's a valuable data point. I'm also running with it disabled, no apparent problems here either.
I'd like to push this mmconf patch upstream in some shape or form, so if anyone would like to chime in how to approach this I'd be glad. I could just wrap the offending line with "#if !CONFIG_MMCONF_SUPPORT_DEFAULT" or something, if that's acceptable. If we can't figure out what it affects, however, perhaps we're just as well off removing it?
It appears that the write to register 0x78 is attempting to switch the LPC device from subtractive decode to positive decode. Presumably the hang is due to the LPC device not being configured for some IO or memory range. Why you're seeing the hang only when mmconfig is enabled, I have no idea.
I'd vote for removing that line, but I have no means to check whether that would break any board.