Enable support for printing the LTSSM link state for debugging PCI
when link is down.
Signed-off-by: Faiz Abbas <faiz_abbas@xxxxxx>
---
drivers/pci/dwc/pci-dra7xx.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 34427a6..7b150b0 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -98,6 +98,18 @@ struct dra7xx_pcie_of_data {
#define to_dra7xx_pcie(x) dev_get_drvdata((x)->dev)
+static char state[][20] = {
+ "DETECT_QUIET", "DETECT_ACT", "POLL_ACTIVE", "POLL_COMPLIANCE",
+ "POLL_CONFIG", "PRE_DETECT_QUIET", "DETECT_WAIT", "CFG_LINKWD_START",
+ "CFG_LINKWD_ACEPT", "CFG_LANENUM_WAIT", "CFG_LANENUM_ACEPT",
+ "CFG_COMPLETE", "CFG_IDLE", "RCVRY_LOCK", "RCVRY_SPEED",
+ "RCVRY_RCVRCFG", "RCVRY_IDLE", "L0", "L0S", "L123_SEND_EIDLE",
+ "L1_IDLE", "L2_IDLE", "L2_WAKE", "DISABLED_ENTRY", "DISABLED_IDLE",
+ "DISABLED", "LPBK_ENTRY", "LPBK_ACTIVE", "LPBK_EXIT",
+ "LPBK_EXIT_TIMEOUT", "HOT_RESET_ENTRY", "HOT_RESET", "RCVRY_EQ0",
+ "RCVRY_EQ1", "RCVRY_EQ2", "RCVRY_EQ3"
+};
+
static inline u32 dra7xx_pcie_readl(struct dra7xx_pcie *pcie, u32 offset)
{
return readl(pcie->base + offset);
@@ -118,6 +130,15 @@ static int dra7xx_pcie_link_up(struct dw_pcie *pci)
{
struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pci);
u32 reg = dra7xx_pcie_readl(dra7xx, PCIECTRL_DRA7XX_CONF_PHY_CS);
+ u32 cmd_reg;
+ u32 ltssm_state;
+
+ if (!(reg & LINK_UP)) {
+ cmd_reg = dra7xx_pcie_readl(dra7xx,
+ PCIECTRL_DRA7XX_CONF_DEVICE_CMD);
+ ltssm_state = (cmd_reg & GENMASK(7, 2)) >> 2;
+ dev_err(pci->dev, "Link state:%s\n", state[ltssm_state]);
+ }
return !!(reg & LINK_UP);
}
--
2.7.4
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