[PATCH AUTOSEL 5.7 38/53] drm/sun4i: mixer: Call of_dma_configure if there's an IOMMU

Sasha Levin
2020-07-02T01:34:26Z

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/9a4daf438dd3f2fe07afb23688bfb793a0613d7d.1589378833.git-series.maxime@cerno.tech
(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
--
2.25.1