diff options
Diffstat (limited to 'drivers/pci/controller/cadence/pci-j721e.c')
| -rw-r--r-- | drivers/pci/controller/cadence/pci-j721e.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/drivers/pci/controller/cadence/pci-j721e.c b/drivers/pci/controller/cadence/pci-j721e.c index bae829ac759e..c014220d2b24 100644 --- a/drivers/pci/controller/cadence/pci-j721e.c +++ b/drivers/pci/controller/cadence/pci-j721e.c @@ -277,6 +277,25 @@ static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie) if (!ret) offset = args.args[0]; + /* + * The PCIe Controller's registers have different "reset-values" + * depending on the "strap" settings programmed into the PCIEn_CTRL + * register within the CTRL_MMR memory-mapped register space. + * The registers latch onto a "reset-value" based on the "strap" + * settings sampled after the PCIe Controller is powered on. + * To ensure that the "reset-values" are sampled accurately, power + * off the PCIe Controller before programming the "strap" settings + * and power it on after that. The runtime PM APIs namely + * pm_runtime_put_sync() and pm_runtime_get_sync() will decrement and + * increment the usage counter respectively, causing GENPD to power off + * and power on the PCIe Controller. + */ + ret = pm_runtime_put_sync(dev); + if (ret < 0) { + dev_err(dev, "Failed to power off PCIe Controller\n"); + return ret; + } + ret = j721e_pcie_set_mode(pcie, syscon, offset); if (ret < 0) { dev_err(dev, "Failed to set pci mode\n"); @@ -295,6 +314,12 @@ static int j721e_pcie_ctrl_init(struct j721e_pcie *pcie) return ret; } + ret = pm_runtime_get_sync(dev); + if (ret < 0) { + dev_err(dev, "Failed to power on PCIe Controller\n"); + return ret; + } + /* Enable ACSPCIE refclk output if the optional property exists */ syscon = syscon_regmap_lookup_by_phandle_optional(node, "ti,syscon-acspcie-proxy-ctrl"); @@ -531,7 +556,7 @@ static int j721e_pcie_probe(struct platform_device *pdev) ret = j721e_pcie_ctrl_init(pcie); if (ret < 0) { - dev_err_probe(dev, ret, "pm_runtime_get_sync failed\n"); + dev_err_probe(dev, ret, "j721e_pcie_ctrl_init failed\n"); goto err_get_sync; } |