[PATCH v2 1/3] PCI: trace: Add PCI controller LTSSM transition tracepoint
From: Shawn Lin <shawn.lin@rock-chips.com>
Date: 2026-01-09 03:35:33
Also in:
linux-doc, linux-pci, linux-rockchip
Subsystem:
pci native host bridge and endpoint drivers, pci subsystem, the rest, tracing · Maintainers:
Lorenzo Pieralisi, Krzysztof Wilczyński, Manivannan Sadhasivam, Bjorn Helgaas, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
Some platforms may provide LTSSM trace functionality, recording historical LTSSM state transition information. This is very useful for debugging, such as when certain devices cannot be recognized or link broken during test. Implement the pci controller tracepoint for recording LTSSM and rate. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> --- Changes in v2: None drivers/pci/trace.c | 1 + include/trace/events/pci_controller.h | 44 +++++++++++++++++++++++++++++++++++ 2 files changed, 45 insertions(+) create mode 100644 include/trace/events/pci_controller.h
diff --git a/drivers/pci/trace.c b/drivers/pci/trace.c
index cf11abc..c1da9d3 100644
--- a/drivers/pci/trace.c
+++ b/drivers/pci/trace.c@@ -9,3 +9,4 @@ #define CREATE_TRACE_POINTS #include <trace/events/pci.h> +#include <trace/events/pci_controller.h>
diff --git a/include/trace/events/pci_controller.h b/include/trace/events/pci_controller.h
new file mode 100644
index 0000000..47d54c6
--- /dev/null
+++ b/include/trace/events/pci_controller.h@@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM pci_controller + +#if !defined(_TRACE_HW_EVENT_PCI_CONTROLLER_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_HW_EVENT_PCI_CONTROLLER_H + +#include <uapi/linux/pci_regs.h> +#include <linux/tracepoint.h> + +TRACE_EVENT(pcie_ltssm_state_transition, + TP_PROTO(const char *dev_name, const char *state, u32 rate), + TP_ARGS(dev_name, state, rate), + + TP_STRUCT__entry( + __string(dev_name, dev_name) + __string(state, state) + __field(u32, rate) + ), + + TP_fast_assign( + __assign_str(dev_name); + __assign_str(state); + __entry->rate = rate; + ), + + TP_printk("dev: %s state: %s rate: %s", + __get_str(dev_name), __get_str(state), + __print_symbolic(__entry->rate, + { PCIE_SPEED_2_5GT, "2.5 GT/s" }, + { PCIE_SPEED_5_0GT, "5.0 GT/s" }, + { PCIE_SPEED_8_0GT, "8.0 GT/s" }, + { PCIE_SPEED_16_0GT, "16.0 GT/s" }, + { PCIE_SPEED_32_0GT, "32.0 GT/s" }, + { PCIE_SPEED_64_0GT, "64.0 GT/s" }, + { PCI_SPEED_UNKNOWN, "Unknown" } + ) + ) +); + +#endif /* _TRACE_HW_EVENT_PCI_CONTROLLER_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h>
--
2.7.4