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From: Hans Zhang <18255117159@163.com>
To: Aksh Garg <a-garg7@ti.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 22:54:14 +0800	[thread overview]
Message-ID: <5a771c43-bbba-49ce-9df8-fdd618289334@163.com> (raw)
In-Reply-To: <d9d4aa30-8d30-4025-abde-0325e102fd8d@ti.com>



On 5/20/26 15:26, Aksh Garg wrote:
> 
> 
> 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().

Hi Aksh,

Will add.


> 
>> 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.
> 

Will change.

Best regards,
Hans

>> +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 */


  reply	other threads:[~2026-05-20 14:55 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
2026-05-20 14:54     ` Hans Zhang [this message]
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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