drm/exynos: g2d userptr memory corruption

[Tobias Jakobi]

Tobias Jakobi wrote:
> Next I looked into Jerome's question about whethere the G2D is
> cache coherent with the CPU. I looked into old Android code and
> found FIMG2D_AXI_MODE_REG, a register that currently isn't
> touched in the DRM code.
> It seems to manipulate signals to the AXI Master interface.
> 
> The register looks like this:
> [0:3] ARCACHE
> [4:7] AWCACHE
> [8:15] ARUSERS
> [16:23] AWUSERS
> [24:25] MaxBurstLength
Correction, it looks like this:
[0:3] ARCACHE
[4:7] AWCACHE
[8:12] ARUSERS
[16:20] AWUSERS
[24:25] MaxBurstLength
(the rest of the bits are reserved)

With best wishes,
Tobias