Decoder doesn't support linear tiling

Hello, I tried to display decoded NV12 surface using Vulkan in zero-copy mode
(import PRIME fd into Vulkan Memory),
but since the NV12 surface is not defaulted to linear tiling, the result is not correct.

I tried to allocate custom VA surface in linear tiling, using `drm_intel_bo_alloc`, `drm_intel_bo_gem_export_prime`, `VASurfaceAttribExternalBuffers`.
But the decoded NV12 data is still not in linear layout, but in some tiling or macroblock order.
It seems the decoder doesn't care the tiling of the output surface.

So, is this a bug, or simply I can't create decoded NV12 frame in linear tiling.

Thank you!