Re: [PATCH v7 0/3] PCI: cadence: Add LTSSM debugfs

[Aksh Garg]

On 11/06/26 22:29, Hans Zhang wrote:
> Hi,
>
> This series adds debugfs support to the Cadence PCIe controller driver,
> allowing users to read the current LTSSM state of the link for debugging
> purposes.
>
> Patch 1 introduces a new flag 'is_hpa' in the cdns_pcie structure to
> distinguish HPA (High Performance Architecture) IP platforms from LGA
> (Legacy Architecture) IP platforms, as they have different register
> layouts for LTSSM status.
>
> Patch 2 implements the debugfs file "ltssm_status" for HPA IP under a
> per-device directory. It reads the LTSSM state from the appropriate
> hardware register based on the 'is_hpa' flag and displays both a
> descriptive string and the raw value.
>
> Patch 3 adds LTSSM debugfs support for LGA IP, utilizing a new callback
> 'get_lga_ltssm' in cdns_pcie_ops to read the LTSSM state from the LGA
> register. The debugfs interface now supports both IP types seamlessly.
>
> =====================
> Test:
> root@orangepi6plus:~# ls -l /sys/kernel/debug/cdns_pcie_a0*
> /sys/kernel/debug/cdns_pcie_a010000.pcie:
> total 0
> -r--r--r-- 1 root root 0 Jan  1  1970 ltssm_status
>
> /sys/kernel/debug/cdns_pcie_a0c0000.pcie:
> total 0
> -r--r--r-- 1 root root 0 Jan  1  1970 ltssm_status
>
> /sys/kernel/debug/cdns_pcie_a0e0000.pcie:
> total 0
> -r--r--r-- 1 root root 0 Jan  1  1970 ltssm_status
> root@orangepi6plus:~#
> root@orangepi6plus:~#
> root@orangepi6plus:~# cat /sys/kernel/debug/cdns_pcie_a0*/ltss*
> L0_STATE (0x29)
> L0_STATE (0x29)
> L0_STATE (0x29)
> root@orangepi6plus:~#
> root@orangepi6plus:~# uname -a
> Linux orangepi6plus 7.1.0-rc3-00007-ge3963f3f4e31 #62 SMP PREEMPT Tue May 19 20:28:24 CST 2026 aarch64 aarch64 aarch64 GNUx
> =====================
>
> ---

Hi,

I have tested the series for LGA IP:

Tested-by: Aksh Garg <a-garg7@xxxxxx>

Regards,
Aksh Garg