Re: [PATCH v7 2/3] PCI: cadence: Add HPA IP debugfs for LTSSM status

[Hans Zhang]

On 7/1/26 13:19, Manivannan Sadhasivam wrote:
> On Fri, Jun 12, 2026 at 12:59:32AM +0800, 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@xxxxxxx>
> > This patch doesn't apply cleanly on top of v7.2-rc1. Please rebase 
and resend
> after incorporating below comments.

Hi Mani,

Will rebase and resend it.


> > ---
> >   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 | 211 ++++++++++++++++++
> >   .../cadence/pcie-cadence-host-hpa.c           |  21 +-
> >   drivers/pci/controller/cadence/pcie-cadence.h | 153 +++++++++++++
> >   7 files changed, 403 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
>
> July 2026
>
> > +Contact:	Hans Zhang <18255117159@xxxxxxx>
> > +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"
>
> As Sashiko pointed out, selecting PCIE_CADENCE_DEBUGFS as m and
> PCIE_CADENCE_HOST as y will cause build error. You can just make
> PCIE_CADENCE_DEBUGFS as 'bool' to avoid this issue.

Thank you.


Best regards,
Hans


> - Mani