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Subject[PATCH v2] dwc: dra7xx: Print link state to console for debug
Date
Enable support for printing the LTSSM link state for debugging PCI
when link is down.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>
---
v2:
1. Changed dev_err() to dev_dbg()
2. Changed static char array to static const char * const
3. format changes

drivers/pci/dwc/pci-dra7xx.c | 48 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)

diff --git a/drivers/pci/dwc/pci-dra7xx.c b/drivers/pci/dwc/pci-dra7xx.c
index 34427a6..0e70e77 100644
--- a/drivers/pci/dwc/pci-dra7xx.c
+++ b/drivers/pci/dwc/pci-dra7xx.c
@@ -98,6 +98,45 @@ struct dra7xx_pcie_of_data {

#define to_dra7xx_pcie(x) dev_get_drvdata((x)->dev)

+static const char * const state[] = {
+ "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 +157,15 @@ 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_dbg(pci->dev, "Link state:%s\n", state[ltssm_state]);
+ }

return !!(reg & LINK_UP);
}
--
2.7.4
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