From: Maxime Ripard maxime@cerno.tech

[ Upstream commit 842ec61f4006a6477a9deaedd69131e9f46e4cb5 ]

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.

Reviewed-by: Paul Kocialkowski paul.kocialkowski@bootlin.com Signed-off-by: Maxime Ripard maxime@cerno.tech Link: https://patchwork.freedesktop.org/patch/msgid/9a4daf438dd3f2fe07afb23688bfb7... (cherry picked from commit b718102dbdfd0285ad559687a30e27cc9124e592) [Maxime: Applied to -fixes since it missed the merge window and display is broken without it] Signed-off-by: Maxime Ripard maxime@cerno.tech Signed-off-by: Sasha Levin sashal@kernel.org --- 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 4a64f7ae437a8..19b3b41847046 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