drm/amdgpu/display: Multiple fixed-point implementations

[Deucher, Alexander]

> -----Original Message-----
> From: amd-gfx [mailto:amd-gfx-bounces at lists.freedesktop.org] On Behalf
> Of Hristo Venev
> Sent: Saturday, December 10, 2016 5:29 AM
> To: amd-gfx at lists.freedesktop.org
> Subject: drm/amdgpu/display: Multiple fixed-point implementations
> 
> There are at least three implementations of fixed-point arithmetic in
> drm/amdgpu/display: fixed31_32 (signed 32-32), fixed32_32 (unsigned 32-
> 32) and bw_fixed (signed 40-24). I don't think fixed-point arithmetic
> implementations belong in drivers.
> 
> There already are two implementations of fixed-point in drm: fixed20_12
> (unsigned 20-12) and drm_fixp (signed 32-32). The latter could be used
> instead of fixed31_32.
> 
> Maybe we could use a standard fixed-point interface and share the
> source code between most (or all) of the implementations. This is one
> of the things that can be done before merging DC and is not too driver-
> specific. What do you guys think?

Sure.  It would be nice to unify them especially if other drivers need them at some point.

Alex