[PATCH v4 0/3] PCI Controller event and LTSSM tracepoint support
Shawn Lin
shawn.lin at rock-chips.com
Tue Feb 24 00:49:47 PST 2026
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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