On 10/12/2010 09:33 AM, Avi Kivity wrote:
Aha! The piix4 specification updates says:
• IRQ9OUT#/GPO29 should be labeled as IRQ9OUT/GPO29
Even more explicitly:
- IRQ9OUT# Is Active HI
Problem: The signal identified as IRQ9OUT#/GPO29, pin F3, is not active level LO, it is active level HI, when APIC Chip Select (XBCS[8]) is set. Implication: This signal is typically used in Dual Processor capable systems and is connected to an IOAPIC. If the IOAPIC input is programmed for level LO, and SCIs or SM Bus events in the PIIX4/PIIX4E/PIIX4M are programmed to be reported on IRQ9OUT, devices using these will not be recognized by the IOAPIC and will not work correctly. Workaround: Program the appropriate input of the IOAPIC to active level HI. Status: This will not be fixed in the PIIX4/PIIX4E/PIIX4M. This is planned to be incorporated into the PIIX4 datasheet as a specification change.