[PATCH 39/49] drm/ttm: make ttm_bo_man_init/takedown take type + args

[Dave Airlie]

> That was not what I was talking about. Take a look at what those fields
> are used for :)
>
>
> As far as I see the only usage of the size is in
> ttm_resource_manager_debug(). But this size is actually totally opaque
> to TTM, it could be pages, bytes, fried chicken wings or whatever. In
> other words it would be much better to print it in the debug callback of
> each resource manager.

Size is a bit trickier as the drivers use in a couple of funky places, radeon
pokes inside the range manager and adjust its size post init, and amdgpu
uses size to validate a bunch of bo sizing. These shouldn't be too messy to
workaround.

> The available_caching is completely superfluous as well. The original
> idea what that a driver could specify multiple placements as flags in
> one entry, but no driver ever used that as far as I know and it became
> completely deprecated in 2014 when I moved the lpfn and fpfn into each
> place.
>
>
> The default_caching is used in ttm_bo_select_caching(), but this is
> complete utterly nonsense. It just results in multiple possible cache
> behaviors being selected, which are then fortunately ignored by
> ttm_tt_set_placement_caching :)
>
>
> To be honest I think just removing those parameters and the associated
> caching flags all together is the next logical step.

Definitely something to burn down alright.

Dave.