From: Jon Hunter <jonathanh@nvidia.com>
Date: Thu, 13 Jan 2022 14:31:52 +0000 (+0000)
Subject: arm64: tegra: Disable ISO SMMU for Tegra194
X-Git-Tag: v5.17-rc8~15^2~8^2
X-Git-Url: https://repo.jachan.dev/linux.git/commitdiff_plain/ebea268ea583ba4970df425dfef8c8e21d0a4e12

arm64: tegra: Disable ISO SMMU for Tegra194

Commit e762232f9466 ("arm64: tegra: Add ISO SMMU controller for Tegra194")
added the ISO SMMU for display devices on Tegra194. The SMMU is enabled by
default but not hooked up to the display controllers yet because we do not
have a way to pass frame-buffer memory from the bootloader to the kernel.
However, even though the SMMU is not hooked up to the display controllers'
SMMU faults are being seen if a display is connected. Therefore, keep the
ISO SMMU disabled by default for now.

Fixes: e762232f9466 ("arm64: tegra: Add ISO SMMU controller for Tegra194")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---

diff --git a/arch/arm64/boot/dts/nvidia/tegra194.dtsi b/arch/arm64/boot/dts/nvidia/tegra194.dtsi
index 3c4acfca459d..6005e422c968 100644
--- a/arch/arm64/boot/dts/nvidia/tegra194.dtsi
+++ b/arch/arm64/boot/dts/nvidia/tegra194.dtsi
@@ -1585,7 +1585,7 @@
 			#iommu-cells = <1>;
 
 			nvidia,memory-controller = <&mc>;
-			status = "okay";
+			status = "disabled";
 		};
 
 		smmu: iommu@12000000 {