Re: [PATCH RFC 01/18] accel/qda: Add Qualcomm QDA DSP accelerator driver docs

[Trilok Soni]

On 2/23/2026 11:08 AM, Ekansh Gupta wrote:
> Add initial documentation for the Qualcomm DSP Accelerator (QDA) driver
> integrated in the DRM accel subsystem.
> 
> The new docs introduce QDA as a DRM/accel-based implementation of
> Hexagon DSP offload that is intended as a modern alternative to the
> legacy FastRPC driver in drivers/misc. The text describes the driver
> motivation, high-level architecture and interaction with IOMMU context
> banks, GEM-based buffer management and the RPMsg transport.
> 
> The user-space facing section documents the main QDA IOCTLs used to
> establish DSP sessions, manage GEM buffer objects and invoke remote
> procedures using the FastRPC protocol, along with a typical lifecycle
> example for applications.
> 
> Finally, the driver is wired into the Compute Accelerators
> documentation index under Documentation/accel, and a brief debugging
> section shows how to enable dynamic debug for the QDA implementation.

So existing applications written over character device UAPI needs to be
rewritten over new UAPI and it will be broken once this driver gets
merged? Are we going to keep both the drivers in the Linux kernel
and not deprecate the /char device one? 

Is Qualcomm going to provide the wrapper library in the userspace
so that existing applications by our customers and developers
keep working w/ the newer kernel if the char interface based
driver gets deprecated? It is not clear from your text above. 

---Trilok Soni