[PATCH 07/11] media: Add stream on/off traces and run them in the ioctl
From: Detlev Casanova <detlev.casanova@collabora.com>
Date: 2026-02-12 16:24:01
Also in:
linux-media, linux-rockchip, linux-trace-kernel, lkml
Subsystem:
media input infrastructure (v4l/dvb), the rest, tracing · Maintainers:
Mauro Carvalho Chehab, Linus Torvalds, Steven Rostedt, Masami Hiramatsu
This will automatically add stream on/off tracing for all v4l2 drivers. Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com> --- drivers/media/v4l2-core/v4l2-ioctl.c | 20 ++++++++++++++++++-- include/trace/events/v4l2.h | 28 ++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+), 2 deletions(-)
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index a3b6df0571d6..fd5193fc722e 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c@@ -1963,13 +1963,29 @@ static int v4l_try_fmt(const struct v4l2_ioctl_ops *ops, struct file *file, static int v4l_streamon(const struct v4l2_ioctl_ops *ops, struct file *file, void *arg) { - return ops->vidioc_streamon(file, NULL, *(unsigned int *)arg); + struct v4l2_fh *fh = file_to_v4l2_fh(file); + int err; + + err = ops->vidioc_streamon(file, NULL, *(unsigned int *)arg); + + if (!err) + trace_v4l2_streamon(fh->tgid, fh->fd); + + return err; } static int v4l_streamoff(const struct v4l2_ioctl_ops *ops, struct file *file, void *arg) { - return ops->vidioc_streamoff(file, NULL, *(unsigned int *)arg); + struct v4l2_fh *fh = file_to_v4l2_fh(file); + int err; + + err = ops->vidioc_streamoff(file, NULL, *(unsigned int *)arg); + + if (!err) + trace_v4l2_streamoff(fh->tgid, fh->fd); + + return err; } static int v4l_g_tuner(const struct v4l2_ioctl_ops *ops, struct file *file,
diff --git a/include/trace/events/v4l2.h b/include/trace/events/v4l2.h
index 248bc09bfc99..bec310eaedc7 100644
--- a/include/trace/events/v4l2.h
+++ b/include/trace/events/v4l2.h@@ -262,6 +262,34 @@ DEFINE_EVENT(vb2_v4l2_event_class, vb2_v4l2_qbuf, TP_ARGS(q, vb) ); +DECLARE_EVENT_CLASS(v4l2_stream_class, + TP_PROTO(u32 tgid, u32 fd), + TP_ARGS(tgid, fd), + + TP_STRUCT__entry( + __field(u32, tgid) + __field(u32, fd) + ), + + TP_fast_assign( + __entry->tgid = tgid; + __entry->fd = fd; + ), + + TP_printk("tgid = %u, fd = %u", + __entry->tgid, __entry->fd) +); + +DEFINE_EVENT(v4l2_stream_class, v4l2_streamon, + TP_PROTO(u32 tgid, u32 fd), + TP_ARGS(tgid, fd) +); + +DEFINE_EVENT(v4l2_stream_class, v4l2_streamoff, + TP_PROTO(u32 tgid, u32 fd), + TP_ARGS(tgid, fd) +); + #endif /* if !defined(_TRACE_V4L2_H) || defined(TRACE_HEADER_MULTI_READ) */ /* This part must be outside protection */
--
2.53.0