xref: /linux/Documentation/trace/events-pci-controller.rst (revision 40286d6379aacfcc053253ef78dc78b09addffda)
1*a3966a6fSShawn Lin.. SPDX-License-Identifier: GPL-2.0
2*a3966a6fSShawn Lin
3*a3966a6fSShawn Lin======================================
4*a3966a6fSShawn LinSubsystem Trace Points: PCI Controller
5*a3966a6fSShawn Lin======================================
6*a3966a6fSShawn Lin
7*a3966a6fSShawn LinOverview
8*a3966a6fSShawn Lin========
9*a3966a6fSShawn LinThe PCI controller tracing system provides tracepoints to monitor controller
10*a3966a6fSShawn Linlevel information for debugging purpose. The events normally show up here:
11*a3966a6fSShawn Lin
12*a3966a6fSShawn Lin	/sys/kernel/tracing/events/pci_controller
13*a3966a6fSShawn Lin
14*a3966a6fSShawn LinCf. include/trace/events/pci_controller.h for the events definitions.
15*a3966a6fSShawn Lin
16*a3966a6fSShawn LinAvailable Tracepoints
17*a3966a6fSShawn Lin=====================
18*a3966a6fSShawn Lin
19*a3966a6fSShawn Linpcie_ltssm_state_transition
20*a3966a6fSShawn Lin---------------------------
21*a3966a6fSShawn Lin
22*a3966a6fSShawn LinMonitors PCIe LTSSM state transition including state and rate information
23*a3966a6fSShawn Lin::
24*a3966a6fSShawn Lin
25*a3966a6fSShawn Lin    pcie_ltssm_state_transition  "dev: %s state: %s rate: %s\n"
26*a3966a6fSShawn Lin
27*a3966a6fSShawn Lin**Parameters**:
28*a3966a6fSShawn Lin
29*a3966a6fSShawn Lin* ``dev`` - PCIe controller instance
30*a3966a6fSShawn Lin* ``state`` - PCIe LTSSM state
31*a3966a6fSShawn Lin* ``rate`` - PCIe date rate
32*a3966a6fSShawn Lin
33*a3966a6fSShawn Lin**Example Usage**:
34*a3966a6fSShawn Lin
35*a3966a6fSShawn Lin.. code-block:: shell
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37*a3966a6fSShawn Lin    # Enable the tracepoint
38*a3966a6fSShawn Lin    echo 1 > /sys/kernel/debug/tracing/events/pci_controller/pcie_ltssm_state_transition/enable
39*a3966a6fSShawn Lin
40*a3966a6fSShawn Lin    # Monitor events (the following output is generated when a device is linking)
41*a3966a6fSShawn Lin    cat /sys/kernel/debug/tracing/trace_pipe
42*a3966a6fSShawn Lin       kworker/0:0-9       [000] .....     5.600221: pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_EQ2 rate: 8.0 GT/s
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