MIPS/PCI: Call pcie_bus_configure_settings() to set MPS/MRRS

[ Upstream commit 2794f688b2c336e0da85e9f91fed33febbd9f54a ]

Call pcie_bus_configure_settings() on MIPS, like for other platforms.
The function pcie_bus_configure_settings() makes sure the MPS (Max
Payload Size) across the bus is uniform and provides the ability to
tune the MRSS (Max Read Request Size) and MPS (Max Payload Size) to
higher performance values. Some devices will not operate properly if
these aren't set correctly because the firmware doesn't always do it.
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Signed-off-by: NPaul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/20649/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Huacai Chen <chenhuacai@gmail.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/mips/pci/pci-legacy.c

@@ -127,8 +127,12 @@ static void pcibios_scanbus(struct pci_controller *hose)
 	if (pci_has_flag(PCI_PROBE_ONLY)) {
 		pci_bus_claim_resources(bus);
 	} else {
+		struct pci_bus *child;
+
 		pci_bus_size_bridges(bus);
 		pci_bus_assign_resources(bus);
+		list_for_each_entry(child, &bus->children, node)
+			pcie_bus_configure_settings(child);
 	}
 	pci_bus_add_devices(bus);
 }