From d4318c1a79ac49f0726dd23a01d1961757b5f98d Mon Sep 17 00:00:00 2001 From: Shuai Xue Date: Wed, 10 Dec 2025 21:29:06 +0800 Subject: PCI: trace: Add RAS tracepoint to monitor link speed changes MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit PCIe link speed degradation directly impacts system performance and often indicates hardware issues such as faulty devices, physical layer problems, or configuration errors. To this end, add a RAS tracepoint to monitor link speed changes, enabling proactive health checks and diagnostic analysis. The following output is generated when a device is hotplugged: $ echo 1 > /sys/kernel/debug/tracing/events/pci/pcie_link_event/enable $ cat /sys/kernel/debug/tracing/trace_pipe irq/51-pciehp-88 [001] ..... 381.545386: pcie_link_event: 0000:00:02.0 type:4, reason:4, cur_bus_speed:20, max_bus_speed:23, width:1, flit_mode:0, status:DLLLA Suggested-by: Ilpo Järvinen Suggested-by: Matthew W Carlis Suggested-by: Lukas Wunner Signed-off-by: Shuai Xue Signed-off-by: Bjorn Helgaas Reviewed-by: Ilpo Järvinen Link: https://patch.msgid.link/20251210132907.58799-3-xueshuai@linux.alibaba.com --- drivers/pci/hotplug/pciehp_hpc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/pci/hotplug') diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c index bcc51b26d03d..ad5f28f6a8b1 100644 --- a/drivers/pci/hotplug/pciehp_hpc.c +++ b/drivers/pci/hotplug/pciehp_hpc.c @@ -320,7 +320,8 @@ int pciehp_check_link_status(struct controller *ctrl) } pcie_capability_read_word(pdev, PCI_EXP_LNKSTA2, &linksta2); - __pcie_update_link_speed(ctrl->pcie->port->subordinate, lnk_status, linksta2); + __pcie_update_link_speed(ctrl->pcie->port->subordinate, PCIE_HOTPLUG, + lnk_status, linksta2); if (!found) { ctrl_info(ctrl, "Slot(%s): No device found\n", -- cgit v1.2.3