Natalie, Regarding the "IRQ compression" in mp_register_gsi().... Some time ago we invented ioapic_renumber_irq() to handle the case where the ES7000 BIOS is missing the INTERRUPT_OVERRIDES needed to tell that legacy IRQs used pins > 15, and PCI interrupts used pins < 16. In that case, the ES7000 uses es7000_rename_gsi() to simply re-number the IRQs for the lower pins to some unused numbers above the highest GSI in the system -- emulating what the BIOS should have done. Later, GSI compression was also added to mp_register_gsi(): if (triggering == ACPI_LEVEL_SENSITIVE) { gsi = pci_irq++; ... } This GSI "compression" was intended to handle systems which have a large number of sparsely populated IOAPICs. On these systems, the maximum GSI is well above NR_IRQS. While there can be a large number of devices on these boxes, the total in use is actually still below NR_IRQs -- so squeezing the GSIs into the IRQ numbers works. The problem with doing this is that it also compresses the IRQ numbers for the other 99.99% of the systems on earth, causing complexity and bugs, such as several mentioned on this thread. I'm thinking that it would be simpler for the big iron that has GSI's > NR_IRQs, to simply use the existing ioapci_renumber_irq() hook to do whatever compression or re-naming they fancy. This will also allow for simpler systems to remain simple and use identity irq = gsi numbering. (don't get me started on CONFIG_PCI_MSI, that is an independent issue) Also, as we discussed, it would probably be cleaner even on those large systems if the compression algorithm did not re-name every GSI, but only did re-names when it really has to (GSI > NR_IRQS). eg. < gsi = pci_irq++ --- > if (GSI < NR_IRQS) > gsi = irq; > else > BUG_ON(irq_used >= NR_IRQS) > gsi = platform specific algorithm to grab the unused IRQs that > can never have any real devices attached. > irqs_used++; If we had done this, then we wouldn't have needed kimbal's patch. If we do this, then we can delete that workaround on top of workaround. thoughts? -Len - To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html