The main DRM device is actually a virtual device so it doesn't have the iommus property, which is instead on the DMA masters, in this case the mixers. Add a call to of_dma_configure with the mixers DT node but on the DRM virtual device to configure it in the same way than the mixers. Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> --- drivers/gpu/drm/sun4i/sun8i_mixer.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/drivers/gpu/drm/sun4i/sun8i_mixer.c b/drivers/gpu/drm/sun4i/sun8i_mixer.c index 4a64f7ae437a..19b3b4184704 100644 --- a/drivers/gpu/drm/sun4i/sun8i_mixer.c +++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c @@ -452,6 +452,19 @@ static int sun8i_mixer_bind(struct device *dev, struct device *master, mixer->engine.ops = &sun8i_engine_ops; mixer->engine.node = dev->of_node; + if (of_find_property(dev->of_node, "iommus", NULL)) { + /* + * This assume we have the same DMA constraints for + * all our the mixers in our pipeline. This sounds + * bad, but it has always been the case for us, and + * DRM doesn't do per-device allocation either, so we + * would need to fix DRM first... + */ + ret = of_dma_configure(drm->dev, dev->of_node, true); + if (ret) + return ret; + } + /* * While this function can fail, we shouldn't do anything * if this happens. Some early DE2 DT entries don't provide -- git-series 0.9.1