[LinuxBIOS] Missing IRQ table entries; irq_tables.c problem?

Marc Jones Marc.Jones at amd.com
Tue Sep 18 17:15:53 CEST 2007

Jonathan Sturges wrote:
> My apologies, forgot to update the subject line!
>>> One thing I'd like to investigate as well is initializing the IRQ router in
>>> LB.  I've seen some discussion about this in the past, and I've come to the
>>> conclusion that for Geode GX1/CS5530 systems, it should be initialized in
>>> LB rather than Linux.  It also seems like some LB ports do this, and others
>>> do not.
>> Linux does not know the CS5530 as an IRQ router. So it does not change 
>> anything in its registers settings. For this chipset Linux relies on the 
>> BIOS. Or you must patch the kernel. How to make LB fill in the routing 
>> registers with usefull values?
>> Juergen
> Looking at newer Geode targets, some of the CS5536 systems seem to update the IRQ steering registers; see write_pirq_routing_table() in src/mainboard/artecgroup/dbe61/irq_tables.c.  I think that block of code could be adapted to the CS5530.  Is it pretty much understood that setting the IRQ steering registers within that function is the right place?
> -Jonathan
Sounds like the right place to me.

Marc Jones
Senior Firmware Engineer
(970) 226-9684 Office
mailto:Marc.Jones at amd.com

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