How can the device tree / driver be updated to use 4 data lanes instead of 2? I need higher bandwidth; I know the hardware exists for the 4 data lane connections.
The device tree partition can be mounted like this:
- sudo mount /dev/disk/by-partlabel/dtb_a /mnt
/mnt will contain the combined-dtb.dtb file used during boot.
The rubikpi_build.sh script show how to rebuild it.
For quick and dirty changes I’ve just decompiled the tree, edit, recompile, reboot. Obviously device-tree edits can deliver mixed results so I’d test on a target that can be re-flashed without too much pain.
Thank you.
How can I find which line to update in the decompiled file?
If you are using the Raspberry Pi IMX477 Module recommended by us, please note that enabling 4 data lanes may require hardware modifications. The current IMX477 Module may only support 2 data lanes by default. For more technical details, please refer to the link below.
I have confirmed 4 data lanes are electrically connected. However, my application requires 60 Hz stereo streaming, and I am not able to achieve more than 30 FPS. In the qtifmmsrc guide a video_%u device should allow for up to 120 FPS, but in practice I am not able to get anywhere close to this, regardless of the resolution I set.
The IPE capability is slightly above 4K@30FPS, and the video encoder shares the same limitation. Neither the ISP (IPE) nor the video encoder supports 4K@60FPS.
If you require 60FPS, we recommend reducing the resolution for testing.
I can’t get 1920x1080 @ 60 Hz to work either.
We recommend that you contact the sensor FAE to obtain the corresponding register configuration for 4 Data Lanes for debugging.
Ubuntu kernel is open sourced. There’s no need to decompile.
You can get the kernel source by:
git clone --single-branch -b master-next https://git.launchpad.net/~canonical-kernel/ubuntu/+source/linux-qcom/+git/noble
We also have a git mirror in github: GitHub - rubikpi-ai/linux-ubuntu: The Linux kernel used by Ubuntu. · GitHub
in case you want to check the code on the web.