Thread (11 messages) 11 messages, 3 authors, 2020-05-15
STALE2259d
Revisions (2)
  1. v3 [diff vs current]
  2. v4 current

[PATCH v4 5/5] drm/sun4i: mixer: Call of_dma_configure if there's an IOMMU

From: Maxime Ripard <hidden>
Date: 2020-05-13 14:07:41
Also in: linux-devicetree, linux-iommu
Subsystem: drm driver for allwinner de2 and de3 engine, drm drivers, drm drivers and misc gpu patches, drm drivers for allwinner a10, the rest · Maintainers: Chen-Yu Tsai, David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Linus Torvalds

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 <redacted>
---
 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 56cc037fd312..cc4fb916318f 100644
--- a/drivers/gpu/drm/sun4i/sun8i_mixer.c
+++ b/drivers/gpu/drm/sun4i/sun8i_mixer.c
@@ -363,6 +363,19 @@ 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

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