Cannot change usb buffer size

Autonomous Machines Jetson & Embedded Systems Jetson AGX Xavier
1

I want to change the buffer size to enable higher frame rate for my USB3 cameras.
For this I changed the buffer size in the /boot/extlinux/extlinux.conf
file to 1000, however after a reboot the value is changed to 16 again when I print it with

cat /sys/module/usbcore/parameters/usbfs_memory_mb

My extlinux.conf file looks as follows:

TIMEOUT 30
DEFAULT primary

MENU TITLE L4T boot options

LABEL primary
      MENU LABEL primary kernel
      LINUX /boot/Image
      INITRD /boot/initrd
      APPEND ${cbootargs} quiet usbcore.usbfs_memory_mb=1000

# When testing a custom kernel, it is recommended that you create a backup of
# the original kernel and add a new entry to this file so that the device can
# fallback to the original kernel. To do this:
#
# 1, Make a backup of the original kernel
#      sudo cp /boot/Image /boot/Image.backup
#
# 2, Copy your custom kernel into /boot/Image
#
# 3, Uncomment below menu setting lines for the original kernel
#
# 4, Reboot

# LABEL backup
#    MENU LABEL backup kernel
#    LINUX /boot/Image.backup
#    INITRD /boot/initrd
#    APPEND ${cbootargs}

Am I doing anything wrong here? Do I also have to enable USB3 on Xavier or is it enabled by default?

2

I don’t know if the actual edit is valid or not, but many of the parameters were moved from extlinux.conf into the device tree. In the past some of the pre-U-Boot stages needed the boot argument (or other) information, and the device tree was moved from the ext4 partition to instead become a binary partition where those earlier stages had access to the kernel arguments without the need to add an ext4 driver. In more recent releases the Xavier does not even use U-Boot and boots directly from CBoot (and generally speaking it is U-Boot that reads extlinux.conf…not sure how much CBoot looks at this in the most recent release).

If you look for kernel customization information and find the kernel device tree “chosen/bootargs” you will find the new location for what used to be the APPEND of extlinux.conf. You’ll need to flash that tree after editing.