Increase VI5 queue size

Hi Everyone,
I am working on custom sensor which send data in following spec.
1 second = 3200 frames
1 frame = 32kBytes
When am reading data using v4l2 API I can read all packets but most of time there is a drop in packets so that I have increased
queue size to 32 I can able to see improvements. Because kerenel is configure to queue depth to 32 , I can’t increase queue size more than
32. Is any possibility to increase queue size in VI5 queue and v4l2-ioctl.
I have tried following link but no use.
Link : [V4L2] VIDIOC_REQBUFS cannot allocate more than 2GB of buffer

Can anyone give suggestion regarding this issue.
Thanks for your time

Hi Everyone,

I am facing packet drop issue, Could you please look at the scenario and give some idea to debug it or
why it’s causing this issue.

Scenario 1:
Configuration → 1 custom sensor, 1 * 2 lane configuration, 4 Virtual channel, 800 FPS, width of frame is 32kbytes.
Frame reading using v4l2 API.
No frame drop up to 1280000 Frame, When it’s reading more than that there is random frame drop.
Intially I have drop when am reading 800 FPS, Once I increase Request buffer queue in v4l2 API issue solve.

For verification is there any provision to increase vi5 queue.
Can anyone give some idea to debug it.

Thanks for your time.

800 FPS? do you mean frame rate?
Have you boost the system and nvcsi/vi clocks?

Try to modify the QUEUED_BUFFERS in below file.


Hi ShaneCCC,
Thanks for your support. 800 frames per second. I have increased nvcsi and vi clock using link: Use 4 CPU for Multithreading using C in xavier NX - #14 by AlbinRaj0.
I have a doubt, In mc_common.h file queue buffer (#define QUEUED_BUFFERS 4) means what it’s doing. I can configure up 32 in my v4l2 queue buffer but here it’s assigned 4. could you please explain about this macro(QUEUED_BUFFERS).

thanks for your time

It’s internal DMA ring buffer.

Hi ShaneCCC,
Thanks for your support.

After increasing QUEUED_BUFFERS also facing same issue, I can't increase queue in v4l2 API .
Can you give any other suggestion

thanks for your time

Hi ShaneCCC,
I have checked VI5 clock it’s set to 460MHZ, I try to increase it because of max rate set to 460MHZ I can’t able to increase it. Is any possibility to increase max rate to 660MHZ which is mentioned in TRM VI5 engine maximum clock speed of up to 660 MHz .

Thanks for your time