diff options
Diffstat (limited to 'arch/arm/mach-versatile/pci.c')
| -rw-r--r-- | arch/arm/mach-versatile/pci.c | 25 |
1 files changed, 19 insertions, 6 deletions
diff --git a/arch/arm/mach-versatile/pci.c b/arch/arm/mach-versatile/pci.c index e92e5e0705bc..234740d90385 100644 --- a/arch/arm/mach-versatile/pci.c +++ b/arch/arm/mach-versatile/pci.c @@ -295,6 +295,19 @@ int __init pci_versatile_setup(int nr, struct pci_sys_data *sys) __raw_writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2); /* + * For many years the kernel and QEMU were symbiotically buggy + * in that they both assumed the same broken IRQ mapping. + * QEMU therefore attempts to auto-detect old broken kernels + * so that they still work on newer QEMU as they did on old + * QEMU. Since we now use the correct (ie matching-hardware) + * IRQ mapping we write a definitely different value to a + * PCI_INTERRUPT_LINE register to tell QEMU that we expect + * real hardware behaviour and it need not be backwards + * compatible for us. This write is harmless on real hardware. + */ + __raw_writel(0, VERSATILE_PCI_VIRT_BASE+PCI_INTERRUPT_LINE); + + /* * Do not to map Versatile FPGA PCI device into memory space */ pci_slot_ignore |= (1 << myslot); @@ -327,13 +340,13 @@ static int __init versatile_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) { int irq; - /* slot, pin, irq - * 24 1 IRQ_SIC_PCI0 - * 25 1 IRQ_SIC_PCI1 - * 26 1 IRQ_SIC_PCI2 - * 27 1 IRQ_SIC_PCI3 + /* + * Slot INTA INTB INTC INTD + * 31 PCI1 PCI2 PCI3 PCI0 + * 30 PCI0 PCI1 PCI2 PCI3 + * 29 PCI3 PCI0 PCI1 PCI2 */ - irq = IRQ_SIC_PCI0 + ((slot - 24 + pin - 1) & 3); + irq = IRQ_SIC_PCI0 + ((slot + 2 + pin - 1) & 3); return irq; } |