Disable MSI also when pcie-octeon.pcie_disable on

Octeon has an boot-time option to disable pcie.

Since MSI depends on PCI-E, we should also disable MSI also with
this option is on in order to avoid inadvertently accessing PCIe
registers.
Signed-off-by: YunQiang Su <ysu@wavecomp.com>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: pburton@wavecomp.com
Cc: linux-mips@vger.kernel.org
Cc: aaro.koskinen@iki.fi
Cc: stable@vger.kernel.org # v3.3+

arch/mips/pci/msi-octeon.c

@@ -369,7 +369,9 @@ int __init octeon_msi_initialize(void)
 	int irq;
 	struct irq_chip *msi;
 
-	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
+	if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_INVALID) {
+		return 0;
+	} else if (octeon_dma_bar_type == OCTEON_DMA_BAR_TYPE_PCIE) {
 		msi_rcv_reg[0] = CVMX_PEXP_NPEI_MSI_RCV0;
 		msi_rcv_reg[1] = CVMX_PEXP_NPEI_MSI_RCV1;
 		msi_rcv_reg[2] = CVMX_PEXP_NPEI_MSI_RCV2;