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

[Daniel Vetter]

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.

But atm amdgpu and radeon also don't support explicit modifiers in the
kernel driver, so it again all checks out. Or should at least.

Once you add modifier support, you need to wire up all the bits and the
rigth default selection, and it should again pan out.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch