PCI: dwc: Remove default MSI initialization for platform specific MSI chips

Platforms which populate msi_host_init() have their own MSI controller
logic. Writing to MSI control registers on platforms which do not use
Designware's MSI controller logic might have side effects.

To be safe, do not write to MSI control registers if the platform uses
its own MSI controller logic instead of Designware's MSI one.
Signed-off-by: NKishon Vijay Abraham I <kishon@ti.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>

drivers/pci/controller/dwc/pcie-designware-host.c

@@ -626,17 +626,19 @@ void dw_pcie_setup_rc(struct pcie_port *pp)
 
 	dw_pcie_setup(pci);
 
-	num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
-
-	/* Initialize IRQ Status array */
-	for (ctrl = 0; ctrl < num_ctrls; ctrl++) {
-		pp->irq_mask[ctrl] = ~0;
-		dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_MASK +
-					(ctrl * MSI_REG_CTRL_BLOCK_SIZE),
-				    4, pp->irq_mask[ctrl]);
-		dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE +
-					(ctrl * MSI_REG_CTRL_BLOCK_SIZE),
-				    4, ~0);
+	if (!pp->ops->msi_host_init) {
+		num_ctrls = pp->num_vectors / MAX_MSI_IRQS_PER_CTRL;
+
+		/* Initialize IRQ Status array */
+		for (ctrl = 0; ctrl < num_ctrls; ctrl++) {
+			pp->irq_mask[ctrl] = ~0;
+			dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_MASK +
+					    (ctrl * MSI_REG_CTRL_BLOCK_SIZE),
+					    4, pp->irq_mask[ctrl]);
+			dw_pcie_wr_own_conf(pp, PCIE_MSI_INTR0_ENABLE +
+					    (ctrl * MSI_REG_CTRL_BLOCK_SIZE),
+					    4, ~0);
+		}
 	}
 
 	/* Setup RC BARs */