Re: [PATCH v2 11/15] media: microchip-isc: add per-channel gamma LUT controls

[Sakari Ailus]

Hi Balakrishnan,

Thanks for the set.

On Tue, May 12, 2026 at 09:13:35PM +0530, Balakrishnan Sambath wrote:
> Add 64-entry gamma LUT controls for R/G/B channels. Setting any LUT
> overrides V4L2_CID_GAMMA; writing V4L2_CID_GAMMA restores presets.
> Supports SAMA7G5 bipartite encoding.

I'd say hardware this complicated should use parameter buffers like other
similar hardware does. The reasoning is that the userspace gets an
interface that allows passing all relevant parameters to the driver at one
go, with a reasonable expectation on which frame it can be applied to.
Controls provide neither of these.

On top of this, the control framework, while useful for high level
configuration parameters, introduces quite a bit of validation overhead
that can affect performance while the effect of a bad parameter value is
simply bad output and the software setting these values is purpose-built so
it can already take the ranges and steps into account.

-- 
Kind regards,

Sakari Ailus