Rob Herring writes: > On Mon, Apr 16, 2018 at 5:52 PM, Eric Anholt wrote: >> The GPU subsystem node was a workaround to have a central device to >> bind V3D and display to. Following the lead of 246774d17fc0 >> ("drm/etnaviv: remove the need for a gpu-subsystem DT node"), remove >> the subsystem node usage and just create a platform device for the DRM >> device to attach to if any of the subsystem devices are present. >> >> v2: Simplify the DT walking code. >> v3: Always put the node. >> >> Signed-off-by: Eric Anholt >> --- >> .../bindings/display/brcm,bcm-vc4.txt | 7 ----- >> drivers/gpu/drm/vc4/vc4_drv.c | 28 +++++++++++++------ >> drivers/gpu/drm/vc4/vc4_hvs.c | 1 + >> drivers/gpu/drm/vc4/vc4_v3d.c | 1 + >> 4 files changed, 22 insertions(+), 15 deletions(-) > > Reviewed-by: Rob Herring Unfortunately, on further testing, this ends up broken. My guess is that our new platform device isn't on the same bus, so we don't get our dma-ranges translation when we use drm->dev, and that breaks caching behavior.