[PATCH 6.19 526/844] PCI: dwc: Add L1 Substates context to ltssm_status of debugfs

From: Sasha Levin

Date: Sat Feb 28 2026 - 14:00:16 EST


From: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>

[ Upstream commit 679ec639f29cbdaf36bd79bf3e98240fffa335ee ]

DWC core couldn't distinguish LTSSM state among L1.0, L1.1 and L1.2. But
the vendor glue driver may implement additional logic to convey this
information. So add two pseudo definitions for vendor glue drivers to
translate their internal L1 Substates for debugfs to show.

Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>
Signed-off-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
Link: https://patch.msgid.link/1765503205-22184-1-git-send-email-shawn.lin@xxxxxxxxxxxxxx
Stable-dep-of: 180c3cfe3678 ("Revert "PCI: dw-rockchip: Enumerate endpoints based on dll_link_up IRQ"")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/pci/controller/dwc/pcie-designware-debugfs.c | 2 ++
drivers/pci/controller/dwc/pcie-designware.h | 4 ++++
2 files changed, 6 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware-debugfs.c b/drivers/pci/controller/dwc/pcie-designware-debugfs.c
index 0fbf86c0b97e0..df98fee69892b 100644
--- a/drivers/pci/controller/dwc/pcie-designware-debugfs.c
+++ b/drivers/pci/controller/dwc/pcie-designware-debugfs.c
@@ -485,6 +485,8 @@ static const char *ltssm_status_string(enum dw_pcie_ltssm ltssm)
DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ1);
DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ2);
DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_RCVRY_EQ3);
+ DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L1_1);
+ DW_PCIE_LTSSM_NAME(DW_PCIE_LTSSM_L1_2);
default:
str = "DW_PCIE_LTSSM_UNKNOWN";
break;
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 5c429b62cb086..ed1801dd8e39a 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -392,6 +392,10 @@ enum dw_pcie_ltssm {
DW_PCIE_LTSSM_RCVRY_EQ2 = 0x22,
DW_PCIE_LTSSM_RCVRY_EQ3 = 0x23,

+ /* Vendor glue drivers provide pseudo L1 substates from get_ltssm() */
+ DW_PCIE_LTSSM_L1_1 = 0x141,
+ DW_PCIE_LTSSM_L1_2 = 0x142,
+
DW_PCIE_LTSSM_UNKNOWN = 0xFFFFFFFF,
};

--
2.51.0