On Fri, Jan 09, 2026 at 11:29:48AM +0800, Shawn Lin wrote: > The available tracepoint, pcie_ltssm_state_transition, monitors the LTSSM > state > transistion for debugging purpose. Add description about it. > > Signed-off-by: Shawn Lin <[email protected]> > --- > > Changes in v2: None > > Documentation/trace/events-pci-conotroller.rst | 41 > ++++++++++++++++++++++++++ > 1 file changed, 41 insertions(+) > create mode 100644 Documentation/trace/events-pci-conotroller.rst > > diff --git a/Documentation/trace/events-pci-conotroller.rst > b/Documentation/trace/events-pci-conotroller.rst > new file mode 100644 > index 0000000..8253d00 > --- /dev/null > +++ b/Documentation/trace/events-pci-conotroller.rst > @@ -0,0 +1,41 @@ > +.. SPDX-License-Identifier: GPL-2.0 > + > +====================================== > +Subsystem Trace Points: PCI Controller > +====================================== > + > +Overview > +======== > +The PCI controller tracing system provides tracepoints to monitor controller > level > +information for debugging purpose. The events normally show up here: > +up here: > + > + /sys/kernel/tracing/events/pci_controller > + > +Cf. include/trace/events/pci_controller.h for the events definitions. > + > +Available Tracepoints > +===================== > + > +pcie_ltssm_state_transition > +----------------------- > + > +Monitors PCIe LTSSM state transition including state and rate information > +:: > + > + pcie_ltssm_state_transition "dev: %s state: %s rate: %s\n" > + > +**Parameters**: > + > +* ``dev`` - PCIe root port name
'PCIe controller instance' > +* ``state`` - PCIe LTSSM state > +* ``rate`` - PCIe bus speed 'PCIe data rate' > + > +**Example Usage**: > + > + # Enable the tracepoint > + echo 1 > > /sys/kernel/debug/tracing/events/pci/pcie_ltssm_state_transition/enable /sys/kernel/debug/tracing/events/pci_controller/pcie_ltssm_state_transition/enable - Mani -- மணிவண்ணன் சதாசிவம்
