Disable aspm

Disabling PCIe Active State Power Management

This step is necessary to make sure that the USB3 PCIe card receives enough power to run multiple cameras at the same time. Otherwise you will see errors in your logs

...
jetson-1 kernel: pcieport 0000:00:01.0: AER: Corrected error received: id=0020
...

To disable this, modify /boot/extlinux/extlinux.conf as per the following

sudo nano /boot/extlinux/extlinux.conf

Add pcie_aspm=off to the APPEND line

...
LABEL primary
    MENU LABEL primary kernel
    ...
    APPEND ... pcie_aspm=off
...

Save and exit the file. Make sure that this is the only change to the file, as modifying extlinux.conf incorrectly can cause the Jetson to fail to boot!