From aaf22ab4e916afa68a2e1aed4e913b76cbd58276 Mon Sep 17 00:00:00 2001 From: Ray Jui Date: Tue, 15 Sep 2015 17:39:19 -0700 Subject: [PATCH 144/147] PCI: iproc: Improve link detection logic Improve the link detection logic by explicitly querying the link status register to ensure link is active. Also force class to PCI_CLASS_BRIDGE_PCI (0x0604) through the host configuration space register. Signed-off-by: Ray Jui Signed-off-by: Bjorn Helgaas Reviewed-by: Anup Patel Reviewed-by: Scott Branden --- drivers/pci/host/pcie-iproc.c | 29 +++++++++++++++++++++++------ 1 file changed, 23 insertions(+), 6 deletions(-) --- a/drivers/pci/host/pcie-iproc.c +++ b/drivers/pci/host/pcie-iproc.c @@ -60,6 +60,12 @@ #define SYS_RC_INTX_EN 0x330 #define SYS_RC_INTX_MASK 0xf +#define PCIE_LINK_STATUS_OFFSET 0xf0c +#define PCIE_PHYLINKUP_SHIFT 3 +#define PCIE_PHYLINKUP BIT(PCIE_PHYLINKUP_SHIFT) +#define PCIE_DL_ACTIVE_SHIFT 2 +#define PCIE_DL_ACTIVE BIT(PCIE_DL_ACTIVE_SHIFT) + static inline struct iproc_pcie *iproc_data(struct pci_bus *bus) { struct iproc_pcie *pcie; @@ -138,9 +144,15 @@ static void iproc_pcie_reset(struct ipro static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus) { u8 hdr_type; - u32 link_ctrl; + u32 link_ctrl, class, val; u16 pos, link_status; - int link_is_active = 0; + bool link_is_active = false; + + val = readl(pcie->base + PCIE_LINK_STATUS_OFFSET); + if (!(val & PCIE_PHYLINKUP) || !(val & PCIE_DL_ACTIVE)) { + dev_err(pcie->dev, "PHY or data link is INACTIVE!\n"); + return -ENODEV; + } /* make sure we are not in EP mode */ pci_bus_read_config_byte(bus, 0, PCI_HEADER_TYPE, &hdr_type); @@ -150,14 +162,19 @@ static int iproc_pcie_check_link(struct } /* force class to PCI_CLASS_BRIDGE_PCI (0x0604) */ - pci_bus_write_config_word(bus, 0, PCI_CLASS_DEVICE, - PCI_CLASS_BRIDGE_PCI); +#define PCI_BRIDGE_CTRL_REG_OFFSET 0x43c +#define PCI_CLASS_BRIDGE_MASK 0xffff00 +#define PCI_CLASS_BRIDGE_SHIFT 8 + pci_bus_read_config_dword(bus, 0, PCI_BRIDGE_CTRL_REG_OFFSET, &class); + class &= ~PCI_CLASS_BRIDGE_MASK; + class |= (PCI_CLASS_BRIDGE_PCI << PCI_CLASS_BRIDGE_SHIFT); + pci_bus_write_config_dword(bus, 0, PCI_BRIDGE_CTRL_REG_OFFSET, class); /* check link status to see if link is active */ pos = pci_bus_find_capability(bus, 0, PCI_CAP_ID_EXP); pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA, &link_status); if (link_status & PCI_EXP_LNKSTA_NLW) - link_is_active = 1; + link_is_active = true; if (!link_is_active) { /* try GEN 1 link speed */ @@ -181,7 +198,7 @@ static int iproc_pcie_check_link(struct pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA, &link_status); if (link_status & PCI_EXP_LNKSTA_NLW) - link_is_active = 1; + link_is_active = true; } }