diff options
Diffstat (limited to 'drivers/pci/controller/pci-tegra.c')
| -rw-r--r-- | drivers/pci/controller/pci-tegra.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/drivers/pci/controller/pci-tegra.c b/drivers/pci/controller/pci-tegra.c index c86e65708908..dfb13aee6322 100644 --- a/drivers/pci/controller/pci-tegra.c +++ b/drivers/pci/controller/pci-tegra.c @@ -191,6 +191,8 @@ #define RP_LINK_CONTROL_STATUS_DL_LINK_ACTIVE 0x20000000 #define RP_LINK_CONTROL_STATUS_LINKSTAT_MASK 0x3fff0000 +#define RP_LINK_CONTROL_STATUS_2 0x000000b0 + #define PADS_CTL_SEL 0x0000009c #define PADS_CTL 0x000000a0 @@ -226,6 +228,7 @@ #define PADS_REFCLK_CFG_DRVI_SHIFT 12 /* 15:12 */ #define PME_ACK_TIMEOUT 10000 +#define LINK_RETRAIN_TIMEOUT 100000 /* in usec */ struct tegra_msi { struct msi_controller chip; @@ -2108,6 +2111,64 @@ retry: return false; } +static void tegra_pcie_change_link_speed(struct tegra_pcie *pcie) +{ + struct device *dev = pcie->dev; + struct tegra_pcie_port *port; + ktime_t deadline; + u32 value; + + list_for_each_entry(port, &pcie->ports, list) { + /* + * "Supported Link Speeds Vector" in "Link Capabilities 2" + * is not supported by Tegra. tegra_pcie_change_link_speed() + * is called only for Tegra chips which support Gen2. + * So there no harm if supported link speed is not verified. + */ + value = readl(port->base + RP_LINK_CONTROL_STATUS_2); + value &= ~PCI_EXP_LNKSTA_CLS; + value |= PCI_EXP_LNKSTA_CLS_5_0GB; + writel(value, port->base + RP_LINK_CONTROL_STATUS_2); + + /* + * Poll until link comes back from recovery to avoid race + * condition. + */ + deadline = ktime_add_us(ktime_get(), LINK_RETRAIN_TIMEOUT); + + while (ktime_before(ktime_get(), deadline)) { + value = readl(port->base + RP_LINK_CONTROL_STATUS); + if ((value & PCI_EXP_LNKSTA_LT) == 0) + break; + + usleep_range(2000, 3000); + } + + if (value & PCI_EXP_LNKSTA_LT) + dev_warn(dev, "PCIe port %u link is in recovery\n", + port->index); + + /* Retrain the link */ + value = readl(port->base + RP_LINK_CONTROL_STATUS); + value |= PCI_EXP_LNKCTL_RL; + writel(value, port->base + RP_LINK_CONTROL_STATUS); + + deadline = ktime_add_us(ktime_get(), LINK_RETRAIN_TIMEOUT); + + while (ktime_before(ktime_get(), deadline)) { + value = readl(port->base + RP_LINK_CONTROL_STATUS); + if ((value & PCI_EXP_LNKSTA_LT) == 0) + break; + + usleep_range(2000, 3000); + } + + if (value & PCI_EXP_LNKSTA_LT) + dev_err(dev, "failed to retrain link of port %u\n", + port->index); + } +} + static void tegra_pcie_enable_ports(struct tegra_pcie *pcie) { struct device *dev = pcie->dev; @@ -2132,6 +2193,9 @@ static void tegra_pcie_enable_ports(struct tegra_pcie *pcie) tegra_pcie_port_disable(port); tegra_pcie_port_free(port); } + + if (pcie->soc->has_gen2) + tegra_pcie_change_link_speed(pcie); } static void tegra_pcie_disable_ports(struct tegra_pcie *pcie) |