Jetpack 3.3 for TX2(L4T 28.2.1): SMMU disable

Hello,

In the folder: Linux_for_Tegra/rootfs/boot/kernel/dtb
there are several dtb files.

Which dtb should be modified to disable MMU ? How ?

After burning the new dtb, how can I make sure that SMMU is disabled ?

In a previous thread, the file: tegra186-quill-p3310-1000-c03-00-base.dtb is used
But I do not have this file.

The command: sudo ./flash.sh -r -k kernel-dtb jetson-tx2 mmcblk0p1
is used to burn the new dtb.
Should I place the modified dtb in it’s same original location ?

Thank you,
Zvika

Please apply the following change

diff --git a/kernel-dts/tegra186-soc/tegra186-soc-base.dtsi b/kernel-dts/tegra186-soc/tegra186-soc-base.dtsi
index 5534343e96d5..8e2bd15a44ed 100644
--- a/kernel-dts/tegra186-soc/tegra186-soc-base.dtsi
+++ b/kernel-dts/tegra186-soc/tegra186-soc-base.dtsi
@@ -186,7 +186,6 @@
<&tegra_adsp_audio TEGRA_SID_APE>,
<&{/sound} TEGRA_SID_APE>,
<&{/sound_ref} TEGRA_SID_APE>,
- <&{/pcie-controller@10003000} TEGRA_SID_AFI>,
<&{/ahci-sata@3507000} TEGRA_SID_SATA2>,
<&{/aon@c160000} TEGRA_SID_AON>,
<&{/rtcpu@b000000} TEGRA_SID_RCE>,
@@ -1508,8 +1507,6 @@
interrupt-map-mask = <0 0 0 0>;
interrupt-map = <0 0 0 0 &intc 0 72 0x04>;
 
- #stream-id-cells = <1>;
-
bus-range = <0x00 0xff>;
#address-cells = <3>;
#size-cells = <2>;

To confirm whether or not SMMU is enabled for PCIe, check for

cd /sys/kernel/debug/12000000.iommu/masters/

It should have entries like the following which confirms SMMU enabled for PCIe. The absence of the same means that SMMU is disabled for PCIe

0000:00:01.0/
0000:01:00.0/
10003000.pcie-controller/