From 907fce0902539ecde609e485eb2ecd7119a7a623 Mon Sep 17 00:00:00 2001 From: Gabriele Paoloni Date: Tue, 29 Sep 2015 00:03:10 +0800 Subject: [PATCH] PCI: designware: Make "num-lanes" an optional DT property Currently "num-lanes" is read in dw_pcie_host_init(), but it is only used if we call dw_pcie_setup_rc() while bringing up the link. If the link has already been brought up by firmware, we need not call dw_pcie_setup_rc(), and "num-lanes" is unnecessary. Only complain about "num-lanes" if we actually need it and we didn't find a valid value. [bhelgaas: changelog] Signed-off-by: Gabriele Paoloni Signed-off-by: Bjorn Helgaas --- .../devicetree/bindings/pci/designware-pcie.txt | 3 ++- drivers/pci/host/pcie-designware.c | 10 ++++++---- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/Documentation/devicetree/bindings/pci/designware-pcie.txt b/Documentation/devicetree/bindings/pci/designware-pcie.txt index 9f4faa8e8d00..0036ab3065b8 100644 --- a/Documentation/devicetree/bindings/pci/designware-pcie.txt +++ b/Documentation/devicetree/bindings/pci/designware-pcie.txt @@ -14,7 +14,6 @@ Required properties: - interrupt-map-mask and interrupt-map: standard PCI properties to define the mapping of the PCIe interface to interrupt numbers. -- num-lanes: number of lanes to use - clocks: Must contain an entry for each entry in clock-names. See ../clocks/clock-bindings.txt for details. - clock-names: Must include the following entries: @@ -22,6 +21,8 @@ Required properties: - "pcie_bus" Optional properties: +- num-lanes: number of lanes to use (this property should be specified unless + the link is brought already up in BIOS) - reset-gpio: gpio pin number of power good signal - bus-range: PCI bus numbers covered (it is recommended for new devicetrees to specify this property, to keep backwards compatibility a range of 0x00-0xff diff --git a/drivers/pci/host/pcie-designware.c b/drivers/pci/host/pcie-designware.c index b77535f3967b..fb89ca23d9a8 100644 --- a/drivers/pci/host/pcie-designware.c +++ b/drivers/pci/host/pcie-designware.c @@ -534,10 +534,9 @@ int dw_pcie_host_init(struct pcie_port *pp) } } - if (of_property_read_u32(np, "num-lanes", &pp->lanes)) { - dev_err(pp->dev, "Failed to parse the number of lanes\n"); - return -EINVAL; - } + ret = of_property_read_u32(np, "num-lanes", &pp->lanes); + if (ret) + pp->lanes = 0; if (IS_ENABLED(CONFIG_PCI_MSI)) { if (!pp->ops->msi_host_init) { @@ -814,6 +813,9 @@ void dw_pcie_setup_rc(struct pcie_port *pp) case 8: val |= PORT_LINK_MODE_8_LANES; break; + default: + dev_err(pp->dev, "num-lanes %u: invalid value\n", pp->lanes); + return; } dw_pcie_writel_rc(pp, val, PCIE_PORT_LINK_CONTROL); -- 2.20.1