Hi Steven,

在 2026/02/11 星期三 23:40, Manivannan Sadhasivam 写道:
On Wed, Feb 11, 2026 at 09:13:50PM +0800, Shawn Lin wrote:
在 2026/01/22 星期四 10:02, Shawn Lin 写道:
This patch-set adds new pci controller event and LTSSM tracepoint used by host 
drivers
which provide LTSSM trace functionality. The first user is pcie-dw-rockchip 
with a 256
Bytes FIFO for recording LTSSM transition.


Gentle ping...


Merge window is open now, so we can't accept any patches until -rc1. And I'm
also waiting for an Ack from Steven for the tracing part.


I'd appreciate it if you could share any concerns you might have about v4. :)

Thanks.

- Mani

Testing
=========

This series was tested on RK3588/RK3588s EVB1 with NVMe SSD connected to PCIe3 
and PCIe2
root ports.

echo 1 > 
/sys/kernel/debug/tracing/events/pci_controller/pcie_ltssm_state_transition/enable
cat /sys/kernel/debug/tracing/trace_pipe

   # tracer: nop
   #
   # entries-in-buffer/entries-written: 64/64   #P:8
   #
   #                                _-----=> irqs-off/BH-disabled
   #                               / _----=> need-resched
   #                              | / _---=> hardirq/softirq
   #                              || / _--=> preempt-depth
   #                              ||| / _-=> migrate-disable
   #                              |||| /     delay
   #           TASK-PID     CPU#  |||||  TIMESTAMP  FUNCTION
   #              | |         |   |||||     |         |
        kworker/0:0-9       [000] .....     5.600194: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: DETECT_ACT rate: Unknown
        kworker/0:0-9       [000] .....     5.600198: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: DETECT_WAIT rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600199: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: DETECT_ACT rate: Unknown
        kworker/0:0-9       [000] .....     5.600201: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: POLL_ACTIVE rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600202: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: POLL_CONFIG rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600204: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: CFG_LINKWD_START rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600206: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: CFG_LINKWD_ACEPT rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600207: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: CFG_LANENUM_WAI rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600208: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: CFG_LANENUM_ACEPT rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600210: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: CFG_COMPLETE rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600212: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: CFG_IDLE rate: Unknown
        kworker/0:0-9       [000] .....     5.600213: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: L0 rate: 2.5 GT/s
        kworker/0:0-9       [000] .....     5.600214: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_LOCK rate: Unknown
        kworker/0:0-9       [000] .....     5.600216: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_RCVRCFG rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600217: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_SPEED rate: 
Unknown
        kworker/0:0-9       [000] .....     5.600218: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_LOCK rate: Unknown
        kworker/0:0-9       [000] .....     5.600220: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_EQ1 rate: Unknown
        kworker/0:0-9       [000] .....     5.600221: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_EQ2 rate: 8.0 GT/s
        kworker/0:0-9       [000] .....     5.600222: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_EQ3 rate: 8.0 GT/s
        kworker/0:0-9       [000] .....     5.600224: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_LOCK rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600225: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_RCVRCFG rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600226: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_IDLE rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600227: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: L0 rate: 8.0 GT/s
        kworker/0:0-9       [000] .....     5.600228: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_LOCK rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600229: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_RCVRCFG rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600231: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_IDLE rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600232: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: L0 rate: 8.0 GT/s
        kworker/0:0-9       [000] .....     5.600233: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: L123_SEND_EIDLE rate: 
8.0 GT/s
        kworker/0:0-9       [000] .....     5.600234: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: L1_IDLE rate: 8.0 GT/s
        kworker/0:0-9       [000] .....     5.600236: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_LOCK rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600237: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_RCVRCFG rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600238: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: RCVRY_IDLE rate: 8.0 
GT/s
        kworker/0:0-9       [000] .....     5.600239: 
pcie_ltssm_state_transition: dev: a40000000.pcie state: L0 rate: 8.0 GT/s


Changes in v4:
- use TRACE_EVENT_FN to notify when to start and stop the tracepoint,
    and export pci_ltssm_tp_enabled() for host drivers to use
- skip trace if pci_ltssm_tp_enabled() is false.(Steven)
- wrap into 80 columns(Bjorn)

Changes in v3:
- add TRACE_DEFINE_ENUM for all enums(Steven Rostedt)
- Add toctree entry in Documentation/trace/index.rst(Bagas Sanjaya)
- fix mismatch section underline length(Bagas Sanjaya)
- Make example snippets in code block(Bagas Sanjaya)
- warp context into 80 columns and fix the file name(Bjorn)
- reorder variables(Mani)
- rename loop to i; rename en to enable(Mani)
- use FIELD_GET(Mani)
- add comment about how the FIFO works(Mani)

Changes in v2:
- use tracepoint

Shawn Lin (3):
    PCI: trace: Add PCI controller LTSSM transition tracepoint
    Documentation: tracing: Add PCI controller event documentation
    PCI: dw-rockchip: Add pcie_ltssm_state_transition trace support

   Documentation/trace/events-pci-controller.rst |  42 ++++++++++
   Documentation/trace/index.rst                 |   1 +
   drivers/pci/controller/dwc/pcie-dw-rockchip.c | 111 
++++++++++++++++++++++++++
   drivers/pci/trace.c                           |  20 +++++
   include/linux/pci.h                           |   4 +
   include/trace/events/pci_controller.h         |  57 +++++++++++++
   6 files changed, 235 insertions(+)
   create mode 100644 Documentation/trace/events-pci-controller.rst
   create mode 100644 include/trace/events/pci_controller.h



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