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    "id": 2234756,
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        "name": "Linux PCI development",
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    "msgid": "<20260508034101.1910036-1-18255117159@163.com>",
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    "date": "2026-05-08T03:40:59",
    "name": "[v4,0/2] PCI: cadence: Add LTSSM debugfs",
    "submitter": {
        "id": 89937,
        "url": "http://patchwork.ozlabs.org/api/1.2/people/89937/?format=api",
        "name": "Hans Zhang",
        "email": "18255117159@163.com"
    },
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            "web_url": "http://patchwork.ozlabs.org/project/linux-pci/list/?series=503315",
            "date": "2026-05-08T03:40:59",
            "name": "PCI: cadence: Add LTSSM debugfs",
            "version": 4,
            "mbox": "http://patchwork.ozlabs.org/series/503315/mbox/"
        }
    ],
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        "From": "Hans Zhang <18255117159@163.com>",
        "To": "bhelgaas@google.com,\n\tlpieralisi@kernel.org,\n\tkwilczynski@kernel.org,\n\tmani@kernel.org,\n\thans.zhang@cixtech.com",
        "Cc": "robh@kernel.org,\n\tmpillai@cadence.com,\n\tlinux-pci@vger.kernel.org,\n\tlinux-kernel@vger.kernel.org,\n\tHans Zhang <18255117159@163.com>",
        "Subject": "[PATCH v4 0/2] PCI: cadence: Add LTSSM debugfs",
        "Date": "Fri,  8 May 2026 11:40:59 +0800",
        "Message-Id": "<20260508034101.1910036-1-18255117159@163.com>",
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    },
    "content": "Hi,\n\nThis series adds debugfs support to the Cadence PCIe controller driver,\nallowing users to read the current LTSSM state of the link for debugging\npurposes.\n\nPatch 1 introduces a new flag 'is_hpa' in the cdns_pcie structure to\ndistinguish HPA (High Performance Architecture IP) platforms, which\nhave a different register layout for LTSSM status.\n\nPatch 2 implements the debugfs file \"ltssm_status\" under a per-device\ndirectory. It reads the LTSSM state from the appropriate hardware register\nbased on the 'is_hpa' flag and displays both a descriptive string and the\nraw value.\n\n=====================\nTest:\nroot@orangepi6plus:~# ls -l /sys/kernel/debug/cdns_pcie_a0*\n/sys/kernel/debug/cdns_pcie_a010000.pcie:\ntotal 0\n-r--r--r-- 1 root root 0 Jan  1  1970 ltssm_status\n\n/sys/kernel/debug/cdns_pcie_a0c0000.pcie:\ntotal 0\n-r--r--r-- 1 root root 0 Jan  1  1970 ltssm_status\n\n/sys/kernel/debug/cdns_pcie_a0e0000.pcie:\ntotal 0\n-r--r--r-- 1 root root 0 Jan  1  1970 ltssm_status\nroot@orangepi6plus:~# \nroot@orangepi6plus:~# \nroot@orangepi6plus:~# cat /sys/kernel/debug/cdns_pcie_a0*/ltss*\nL0_STATE (0x29)\nL0_STATE (0x29)\nL0_STATE (0x29)\nroot@orangepi6plus:~# \nroot@orangepi6plus:~# uname -a\nLinux orangepi6plus 7.1.0-rc2-00377-gb898336dec53-dirty #43 SMP PREEMPT Fri May  8 11:15:00 CST 2026 aarch64 aarch64 aarch64 GNU/Linux\n=====================\n\n---\nChanges for v4:\n- Remove the copyright email address of the author of pcie-cadence-debugfs.c (Mani)\n- Add cdns_pcie_hpa_host_disable() (Mani)\n- Use DEFINE_SHOW_ATTRIBUTE() (Mani & Sashiko)\n\nChanges for v3:\nhttps://patchwork.kernel.org/project/linux-pci/patch/20260406103237.1203127-1-18255117159@163.com/\n\n- Export cdns_pcie_debugfs_deinit (Mani)\n- pcie-cadence-ep.c pcie-cadence-host.c pci-sky1.c call cdns_pcie_debugfs_deinit\n\nChanges for v2:\nhttps://patchwork.kernel.org/project/linux-pci/patch/20260321033035.3008585-3-18255117159@163.com/\n\n- s/DW_PCIE_LTSSM_NAME/CDNS_PCIE_LTSSM_NAME/\n- S/January 2026/March 2026/\n- EXPORT_SYMBOL_GPL(cdns_pcie_debugfs_init); // Resolve the following error issues.\n  >> ERROR: modpost: \"cdns_pcie_debugfs_init\" [drivers/pci/controller/cadence/pcie-cadence-host-mod.ko] undefined!\n  >> ERROR: modpost: \"cdns_pcie_debugfs_init\" [drivers/pci/controller/cadence/pcie-cadence-ep-mod.ko] undefined!\n\nv1:\nhttps://patchwork.kernel.org/project/linux-pci/cover/20260315155514.127255-1-18255117159@163.com/\n\nHans Zhang (2):\n  PCI: cadence: Add HPA architecture flag\n  PCI: cadence: Add debugfs property to provide LTSSM status of the PCIe\n    link\n\n Documentation/ABI/testing/debugfs-cdns-pcie   |   5 +\n drivers/pci/controller/cadence/Kconfig        |   9 +\n drivers/pci/controller/cadence/Makefile       |   1 +\n drivers/pci/controller/cadence/pci-sky1.c     |   4 +\n .../controller/cadence/pcie-cadence-debugfs.c | 208 ++++++++++++++++++\n .../pci/controller/cadence/pcie-cadence-ep.c  |   3 +\n .../cadence/pcie-cadence-host-hpa.c           |  20 +-\n .../controller/cadence/pcie-cadence-host.c    |   9 +-\n drivers/pci/controller/cadence/pcie-cadence.h | 152 +++++++++++++\n 9 files changed, 409 insertions(+), 2 deletions(-)\n create mode 100644 Documentation/ABI/testing/debugfs-cdns-pcie\n create mode 100644 drivers/pci/controller/cadence/pcie-cadence-debugfs.c\n\n\nbase-commit: 917719c412c48687d4a176965d1fa35320ec457c"
}