[PATCH v2 1/3] drm: Add the optional .fb_modifier() hook

[Ville Syrjälä]

On Tue, Mar 13, 2018 at 03:38:38PM +0100, Michel Dänzer wrote:
> On 2018-03-13 03:28 PM, Ville Syrjala wrote:
> > From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> > 
> > To make it possible for the core to check the fb pixel format and
> > modifier, we need to first ask the driver to deduce the modifier
> > when the request does not explicitly specify one.
> > 
> > Add a new .fb_modifier() hook for that purpose and convert i915
> > and vc4 to make use if it. All other drivers seem to currently
> > assume linear when the request does not specify anything else,
> > [...]
> 
> That's not true at least for the amdgpu and radeon drivers. The tiling
> mode is communicated via BO metadata.

Well, at least those driver don't do any bo tiling->modifier conversion.
Radeon doesn't do modifiers I suppose, so that part is probably OK.
amggpu might just be broken, not sure.

-- 
Ville Syrjälä
Intel OTC