On Fri, Jul 26, 2024 at 03:49:49PM +0300, Laurent Pinchart wrote: > What is not an option exactly in my description above ? We have multiple > V4L2 drivers for ISPs. They receive ISP parameters from userspace > through a data buffer. It's not allowed to be opaque, but it doesn't > prevent vendor closed-source userspace implementations with additional > *camera* features, as long as the *hardware* features are available to > everybody. How far do you take opaque? In mlx5 we pass command buffers from user to kernel to HW and the kernel does only a little checking. There is a 12kloc file describing the layout of alot of commands: include/linux/mlx5/mlx5_ifc.h There is an open PDF describing in detail some subset of this: https://network.nvidia.com/files/doc-2020/ethernet-adapters-programming-manual.pdf There are in-kernel implementations driving most of those commands. Other commands are only issued by userspace, and we have open source DPDK, rdma-core and UCX implementations driving them. ie, this is really quite good as far as a device providing open source solutions goes. However, no doubt there is more FW capability and commands than even this vast amount documents - so lets guess that propritary code is using this interface with unknown commands too.
