From: gabriele paoloni <gabriele.paoloni@xxxxxxxxxx> Currently num-lanes is read in dw_pcie_host_init(). For a SoC that performs the link-up operation in UEFI, num-lanes is not needed in the DTS; however currently it has to be specified to some random value otherwise dw_pcie_host_init will fail. If the link is brought up in BIOS dw_pcie_setup_rc should not be called. This patch reworks dw_pcie_host_init() so that, if num-lanes is not specified, it sets pp->lanes = 0. If later on dw_pcie_setup_rc is called and pp->num_lanes is not set to a valid value, dw_pcie_setup_rc will send an error message and return. This patch is a follow-up of http://www.spinics.net/lists/linux-pci/msg44394.html Signed-off-by: Gabriele Paoloni <gabriele.paoloni@xxxxxxxxxx> --- Documentation/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 9f4faa8..0036ab3 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 52aa6e3..047ac52 100644 --- a/drivers/pci/host/pcie-designware.c +++ b/drivers/pci/host/pcie-designware.c @@ -482,10 +482,9 @@ 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) { @@ -764,6 +763,9 @@ 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); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
