Neopixel_SPI and Buffer Size

I am using Neopixel SPI to control addressable LED light. Initially, the bufsiz was 4096 which I was able to control 168 LED. I increased the bufsize to 65535 using:

sudo nano /etc/modprobe.d/spidev.conf
options spidev bufsiz=65535
cat /sys/module/spidev/parameters/bufsiz

gives me 65535

But I still cannot control more than 168 LED.

Is there another way to check my buffer size? and this buffer size is directly related the the 19 MOSI pin output?

Thank you.

If the size not change correctly the SPI transfer should be failed when the transfer package more than 4096.

How can I check if it is changed correctly? I only know (cat /sys/module/spidev/parameters/bufsiz)

and it gives me 65535

You can modify the spidev.c to print message to confirm it.

Hello again,
I was trying to build the new kernel to have the spidev,c but I ran out of space.
But my main problem is solved, the buffer size was correctly changed in the board. the main issue was in the Library I used because I should also change this parameter inside it.

Thank you for your help.