Merge tag 'drm/tegra/for-6.1-rc6' of https://gitlab.freedesktop.org/drm/tegra into drm-fixes

drm/tegra: Fixes for v6.1-rc6

This contains a single fix that avoids using the GART on Tegra20 because
it doesn't work well with the way the Tegra DRM driver tries to use it.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Thierry Reding <thierry.reding@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221118121614.3511110-1-thierry.reding@gmail.com

Author: airlied

drivers/gpu/drm/tegra/drm.c

@@ -1093,6 +1093,10 @@ static bool host1x_drm_wants_iommu(struct host1x_device *dev)
 	struct host1x *host1x = dev_get_drvdata(dev->dev.parent);
 	struct iommu_domain *domain;
 
+	/* Our IOMMU usage policy doesn't currently play well with GART */
+	if (of_machine_is_compatible("nvidia,tegra20"))
+		return false;
+
 	/*
 	 * If the Tegra DRM clients are backed by an IOMMU, push buffers are
 	 * likely to be allocated beyond the 32-bit boundary if sufficient

drivers/gpu/host1x/dev.c

@@ -292,6 +292,10 @@ static void host1x_setup_virtualization_tables(struct host1x *host)
 
 static bool host1x_wants_iommu(struct host1x *host1x)
 {
+	/* Our IOMMU usage policy doesn't currently play well with GART */
+	if (of_machine_is_compatible("nvidia,tegra20"))
+		return false;
+
 	/*
 	 * If we support addressing a maximum of 32 bits of physical memory
 	 * and if the host1x firewall is enabled, there's no need to enable