From 55fc280e951ab2b39f3dcb640edc1b1eebc6d173 Mon Sep 17 00:00:00 2001 From: "Rob Herring (Arm)" Date: Mon, 31 Aug 2026 14:43:51 -0500 Subject: Input: tsc2007 - read "ti,poll-period" as u32 The "ti,poll-period" property is documented as a normal uint32 cell. The driver used a u64 helper, which makes the helper type disagree with the schema even though the stored value is still small. Read "ti,poll-period" with the u32 helper matching the documented DT cell size. Assisted-by: Codex:gpt-5-5 Signed-off-by: Rob Herring (Arm) Link: https://patch.msgid.link/20260831194352.1185860-1-robh@kernel.org Signed-off-by: Dmitry Torokhov --- samples/ftrace/sample-trace-array.c | 143 ++++++++++++++++++++++++++++++++++++ 1 file changed, 143 insertions(+) create mode 100644 samples/ftrace/sample-trace-array.c (limited to 'samples/ftrace/sample-trace-array.c') diff --git a/samples/ftrace/sample-trace-array.c b/samples/ftrace/sample-trace-array.c new file mode 100644 index 000000000..414761610 --- /dev/null +++ b/samples/ftrace/sample-trace-array.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0-only +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * Any file that uses trace points, must include the header. + * But only one file, must include the header by defining + * CREATE_TRACE_POINTS first. This will make the C code that + * creates the handles for the trace points. + */ +#define CREATE_TRACE_POINTS +#include "sample-trace-array.h" + +struct trace_array *tr; +static void mytimer_handler(struct timer_list *unused); +static struct task_struct *simple_tsk; + +static void trace_work_fn(struct work_struct *work) +{ + /* + * Disable tracing for event "sample_event". + */ + trace_array_set_clr_event(tr, "sample-subsystem", "sample_event", + false); +} +static DECLARE_WORK(trace_work, trace_work_fn); + +/* + * mytimer: Timer setup to disable tracing for event "sample_event". This + * timer is only for the purposes of the sample module to demonstrate access of + * Ftrace instances from within kernel. + */ +static DEFINE_TIMER(mytimer, mytimer_handler); + +static void mytimer_handler(struct timer_list *unused) +{ + schedule_work(&trace_work); +} + +static void simple_thread_func(int count) +{ + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(HZ); + + /* + * Printing count value using trace_array_printk() - trace_printk() + * equivalent for the instance buffers. + */ + trace_array_printk(tr, _THIS_IP_, "trace_array_printk: count=%d\n", + count); + /* + * Tracepoint for event "sample_event". This will print the + * current value of count and current jiffies. + */ + trace_sample_event(count, jiffies); +} + +static int simple_thread(void *arg) +{ + int count = 0; + unsigned long delay = msecs_to_jiffies(5000); + + /* + * Enable tracing for "sample_event". + */ + trace_array_set_clr_event(tr, "sample-subsystem", "sample_event", true); + + /* + * Adding timer - mytimer. This timer will disable tracing after + * delay seconds. + * + */ + add_timer(&mytimer); + mod_timer(&mytimer, jiffies+delay); + + while (!kthread_should_stop()) + simple_thread_func(count++); + + timer_delete(&mytimer); + cancel_work_sync(&trace_work); + + /* + * trace_array_put() decrements the reference counter associated with + * the trace array - "tr". We are done using the trace array, hence + * decrement the reference counter so that it can be destroyed using + * trace_array_destroy(). + */ + trace_array_put(tr); + + return 0; +} + +static int __init sample_trace_array_init(void) +{ + /* + * Return a pointer to the trace array with name "sample-instance" if it + * exists, else create a new trace array. + * + * NOTE: This function increments the reference counter + * associated with the trace array - "tr". + */ + tr = trace_array_get_by_name("sample-instance", "sched,timer,kprobes"); + + if (!tr) + return -1; + /* + * If context specific per-cpu buffers havent already been allocated. + */ + trace_array_init_printk(tr); + + simple_tsk = kthread_run(simple_thread, NULL, "sample-instance"); + if (IS_ERR(simple_tsk)) { + trace_array_put(tr); + trace_array_destroy(tr); + return -1; + } + + return 0; +} + +static void __exit sample_trace_array_exit(void) +{ + kthread_stop(simple_tsk); + + /* + * We are unloading our module and no longer require the trace array. + * Remove/destroy "tr" using trace_array_destroy() + */ + trace_array_destroy(tr); +} + +module_init(sample_trace_array_init); +module_exit(sample_trace_array_exit); + +MODULE_AUTHOR("Divya Indi"); +MODULE_DESCRIPTION("Sample module for kernel access to Ftrace instances"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1