Hi Greg, On Wed, Jul 15, 2020 at 3:11 AM Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > From: Maxime Ripard <maxime@xxxxxxxxxx> > > [ 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. The iommu driver and DT changes were added in v5.8-rc1. IMO There is no point in backporting this patch to any stable kernel. ChenYu > 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@xxxxxxxxxxx> > Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx> > Link: https://patchwork.freedesktop.org/patch/msgid/9a4daf438dd3f2fe07afb23688bfb793a0613d7d.1589378833.git-series.maxime@xxxxxxxxxx > (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@xxxxxxxxxx> > Signed-off-by: Sasha Levin <sashal@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 18b4881f44814..e24f225d80f1f 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 > > >
