Using Raspberian 13 Trixie (Kernel 6.12.75+rpt-rpi-v8) there si a message "Failed to open /dev/dma_heap/vidbuf_cached."
From lumo:
On Raspberry Pi OS Trixie (Debian 13) with the 6.12+ kernel, the vidbuf_cached heap is no longer created by default in the standard kernel configuration.
This is a deliberate architectural change in the Linux kernel and the Raspberry Pi camera stack. The vidbuf_cached allocator was largely considered redundant because:
Modern kernels handle cache coherency more efficiently via the dma_buf framework.
The system and linux,cma heaps now provide equivalent or better performance for most use cases.
Maintaining a separate cached heap added unnecessary complexity to the driver.
Why Your Application Warns
Your application (likely picamera2 or a wrapper around libcamera) was written with an older assumption: "If vidbuf_cached exists, use it for speed; otherwise, warn."
Since the heap doesn't exist in your kernel, the application logs the warning but automatically switches to the system or cma heap, which is why your camera still works perfectly.
Conclusion
There is no fix needed, and you cannot force the kernel to create it without recompiling the kernel with specific, deprecated flags that the Raspberry Pi team has intentionally removed.
Using Raspberian 13 Trixie (Kernel 6.12.75+rpt-rpi-v8) there si a message "Failed to open /dev/dma_heap/vidbuf_cached."
From lumo:
On Raspberry Pi OS Trixie (Debian 13) with the 6.12+ kernel, the vidbuf_cached heap is no longer created by default in the standard kernel configuration.
This is a deliberate architectural change in the Linux kernel and the Raspberry Pi camera stack. The vidbuf_cached allocator was largely considered redundant because:
Why Your Application Warns
Your application (likely picamera2 or a wrapper around libcamera) was written with an older assumption: "If vidbuf_cached exists, use it for speed; otherwise, warn."
Since the heap doesn't exist in your kernel, the application logs the warning but automatically switches to the system or cma heap, which is why your camera still works perfectly.
Conclusion
There is no fix needed, and you cannot force the kernel to create it without recompiling the kernel with specific, deprecated flags that the Raspberry Pi team has intentionally removed.