From: Aksh Garg <a-garg7@ti.com>
To: Hans Zhang <18255117159@163.com>, <bhelgaas@google.com>,
<lpieralisi@kernel.org>, <kwilczynski@kernel.org>,
<mani@kernel.org>
Cc: <robh@kernel.org>, <mpillai@cadence.com>, <s-vadapalli@ti.com>,
<linux-pci@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v6 2/3] PCI: cadence: Add HPA IP debugfs for LTSSM status
Date: Wed, 20 May 2026 12:56:17 +0530 [thread overview]
Message-ID: <d9d4aa30-8d30-4025-abde-0325e102fd8d@ti.com> (raw)
In-Reply-To: <20260519123609.1595280-3-18255117159@163.com>
On 19/05/26 18:06, Hans Zhang wrote:
> Add debugfs support for HPA-based Cadence PCIe controllers. A new file
> 'ltssm_status' is created under debugfs, allowing users to read the
> current LTSSM state as a string and raw value.
>
> Signed-off-by: Hans Zhang <18255117159@163.com>
> ---
> Documentation/ABI/testing/debugfs-cdns-pcie | 5 +
> drivers/pci/controller/cadence/Kconfig | 9 +
> drivers/pci/controller/cadence/Makefile | 1 +
> drivers/pci/controller/cadence/pci-sky1.c | 4 +
> .../controller/cadence/pcie-cadence-debugfs.c | 208 ++++++++++++++++++
> .../cadence/pcie-cadence-host-hpa.c | 19 +-
> drivers/pci/controller/cadence/pcie-cadence.h | 153 +++++++++++++
> 7 files changed, 398 insertions(+), 1 deletion(-)
> create mode 100644 Documentation/ABI/testing/debugfs-cdns-pcie
> create mode 100644 drivers/pci/controller/cadence/pcie-cadence-debugfs.c
>
> diff --git a/Documentation/ABI/testing/debugfs-cdns-pcie b/Documentation/ABI/testing/debugfs-cdns-pcie
> new file mode 100644
> index 000000000000..c1104e28e4ee
> --- /dev/null
> +++ b/Documentation/ABI/testing/debugfs-cdns-pcie
> @@ -0,0 +1,5 @@
> +What: /sys/kernel/debug/cdns_pcie_<dev>/ltssm_status
> +Date: March 2026
> +Contact: Hans Zhang <18255117159@163.com>
> +Description: (RO) Read will return the current PCIe LTSSM state in both
> + string and raw value.
> \ No newline at end of file
> diff --git a/drivers/pci/controller/cadence/Kconfig b/drivers/pci/controller/cadence/Kconfig
> index 9e651d545973..cb010bc97aad 100644
> --- a/drivers/pci/controller/cadence/Kconfig
> +++ b/drivers/pci/controller/cadence/Kconfig
> @@ -6,6 +6,15 @@ menu "Cadence-based PCIe controllers"
> config PCIE_CADENCE
> tristate
>
> +config PCIE_CADENCE_DEBUGFS
> + tristate "Cadence PCIe debugfs entries"
> + depends on DEBUG_FS
> + depends on PCIE_CADENCE_HOST || PCIE_CADENCE_EP
> + help
> + Say Y here to enable debugfs entries for the PCIe controller. These
> + entries provide various debug features related to the controller and
> + the LTSSM status of link can be displayed.
> +
> config PCIE_CADENCE_HOST
> tristate
> depends on OF
Sashiko pointed the compilation issues when this is build as a module.
The linkage issue needs to be resolved if we want this as a module.
Also, if we build it as m, it would requires MODULE_LICENSE() and
MODULE_DESCRIPTION().
> diff --git a/drivers/pci/controller/cadence/Makefile b/drivers/pci/controller/cadence/Makefile
> index b8ec1cecfaa8..2cdc4617e0c2 100644
> --- a/drivers/pci/controller/cadence/Makefile
> +++ b/drivers/pci/controller/cadence/Makefile
> @@ -4,6 +4,7 @@ pcie-cadence-host-mod-y := pcie-cadence-host-common.o pcie-cadence-host.o pcie-c
> pcie-cadence-ep-mod-y := pcie-cadence-ep.o
>
> obj-$(CONFIG_PCIE_CADENCE) = pcie-cadence-mod.o
> +obj-$(CONFIG_PCIE_CADENCE_DEBUGFS) += pcie-cadence-debugfs.o
> obj-$(CONFIG_PCIE_CADENCE_HOST) += pcie-cadence-host-mod.o
> obj-$(CONFIG_PCIE_CADENCE_EP) += pcie-cadence-ep-mod.o
> obj-$(CONFIG_PCIE_CADENCE_PLAT) += pcie-cadence-plat.o
> diff --git a/drivers/pci/controller/cadence/pci-sky1.c b/drivers/pci/controller/cadence/pci-sky1.c
> index e1f4a98e2ab6..b8632f1d3156 100644
> --- a/drivers/pci/controller/cadence/pci-sky1.c
> +++ b/drivers/pci/controller/cadence/pci-sky1.c
> @@ -221,6 +221,10 @@ MODULE_DEVICE_TABLE(of, of_sky1_pcie_match);
[ ... ]
> /**
> @@ -447,6 +583,7 @@ void cdns_pcie_host_disable(struct cdns_pcie_rc *rc);
> void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
> int where);
> int cdns_pcie_hpa_host_setup(struct cdns_pcie_rc *rc);
> +void cdns_pcie_hpa_host_disable(struct cdns_pcie_rc *rc);
> #else
> static inline int cdns_pcie_host_link_setup(struct cdns_pcie_rc *rc)
> {
> @@ -472,6 +609,10 @@ static inline void cdns_pcie_host_disable(struct cdns_pcie_rc *rc)
> {
> }
>
> +static inline void cdns_pcie_hpa_host_disable(struct cdns_pcie_rc *rc)
> +{
> +}
> +
> static inline void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int devfn,
> int where)
> {
> @@ -535,4 +676,16 @@ bool cdns_pcie_hpa_link_up(struct cdns_pcie *pcie);
>
> extern const struct dev_pm_ops cdns_pcie_pm_ops;
>
> +#ifdef CONFIG_PCIE_CADENCE_DEBUGFS
Use "#if IS_ENABLED(CONFIG_PCIE_CADENCE_DEBUGFS)" to resolve the
compilation error when building as a module.
> +void cdns_pcie_debugfs_deinit(struct cdns_pcie *pci);
> +void cdns_pcie_debugfs_init(struct cdns_pcie *pci);
> +#else
> +static inline void cdns_pcie_debugfs_deinit(struct cdns_pcie *pci)
> +{
> +}
> +static inline void cdns_pcie_debugfs_init(struct cdns_pcie *pci)
> +{
> +}
> +#endif
> +
> #endif /* _PCIE_CADENCE_H */
next prev parent reply other threads:[~2026-05-20 7:26 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-19 12:36 [PATCH v6 0/3] PCI: cadence: Add LTSSM debugfs Hans Zhang
2026-05-19 12:36 ` [PATCH v6 1/3] PCI: cadence: Add HPA architecture flag Hans Zhang
2026-05-19 12:36 ` [PATCH v6 2/3] PCI: cadence: Add HPA IP debugfs for LTSSM status Hans Zhang
2026-05-19 13:20 ` sashiko-bot
2026-05-20 7:26 ` Aksh Garg [this message]
2026-05-20 14:54 ` Hans Zhang
2026-05-19 12:36 ` [PATCH v6 3/3] PCI: cadence: Add LGA " Hans Zhang
2026-05-20 2:34 ` Manikandan Karunakaran Pillai
2026-05-20 2:59 ` Hans Zhang
2026-05-20 4:36 ` Aksh Garg
2026-05-20 4:40 ` Hans Zhang
2026-05-20 5:27 ` Aksh Garg
2026-05-20 5:44 ` Hans Zhang
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