Finding where in kernel a frame is captured

Finding where in kernel a frame is captured

[Ranran]

Hello,

I try to find the exact place where frame are captured in kernel.
I rather find the first place, but if that is a problem, I will use
another method you are familiar with.
I use tegra tx1 with mipi camera of a development kit, so I tried to
add some printing in kernel in vi2_fops.c in
tegra_channel_capture_done() and tegra_channel_capture_frame(), but
nothing is printed while the userspace application capture frames
(using gstreamer).
Although there are no print during frame captured, yet, there are
printed logs in vi2_channel_stop_streaming,
vi2_channel_start_streaming.

Is there any reason why I can't see any logs ? Is the rate is too high ?
Should I try to find where it is captured in v4l2 framework in kernel instead ?

Thanks,
ranran