This patch further improves the iProc PCIe link detection logic by
explicitly querying the link status register to ensure link is active
It also forces class to PCI_CLASS_BRIDGE_PCI (0x0604) through the host
configuration space register
Signed-off-by: Ray Jui <rjui@xxxxxxxxxxxx>
Reviewed-by: Anup Patel <anup.patel@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <sbranden@xxxxxxxxxxxx>
---
drivers/pci/host/pcie-iproc.c | 29 +++++++++++++++++++++++------
1 file changed, 23 insertions(+), 6 deletions(-)
diff --git a/drivers/pci/host/pcie-iproc.c b/drivers/pci/host/pcie-iproc.c
index 80e0541..62e8085 100644
--- 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 iproc_pcie *pcie)
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 iproc_pcie *pcie, struct pci_bus *bus)
}
/* 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 iproc_pcie *pcie, struct pci_bus *bus)
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;
}
}
--
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
