[PATCH 06/22] arm64: dts: qcom: monaco: Reserve low IOVA range for Iris
From: Vikash Garodia
Date: Fri Aug 07 2026 - 04:38:23 EST
Iris VPU reserves IOVA addresses below 0x25800000 (600MB), primarily for
secure non-pixel buffers. DMA into that range, from any other stream id
would triggers unhandled SMMU page faults that cause spontaneous device
reboots. This is readily reproduced with one or more browser tabs
driving multiple concurrent video decode streams.
Add a reserved-memory IOVA reservation node covering [0, 0x25800000]
and reference it from the Iris node so the IOMMU layer keeps DMA
allocations above that boundary.
Fixes: bf6ec39c3f36 ("arm64: dts: qcom: qcs8300: add video node")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
---
arch/arm64/boot/dts/qcom/monaco.dtsi | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/qcom/monaco.dtsi b/arch/arm64/boot/dts/qcom/monaco.dtsi
index cfe39f923224f6c9af0a1b15a84f2fefb90d53d5..048b4490fcafd292e4f8ad7f661121430f9ceb24 100644
--- a/arch/arm64/boot/dts/qcom/monaco.dtsi
+++ b/arch/arm64/boot/dts/qcom/monaco.dtsi
@@ -812,6 +812,17 @@ video_mem: video-region@9be82000 {
reg = <0x0 0x9be82000 0x0 0x700000>;
no-map;
};
+
+ /*
+ * The Iris VPU reserves IOVA below 0x25800000 (600MB),
+ * primarily for non-pixel buffers using different Stream IDs.
+ * DMA into that range triggers unhandled SMMU faults and
+ * spontaneous reboots, so reserve it to keep IOMMU
+ * allocations above this boundary.
+ */
+ iris_iova: iris-iova {
+ iommu-addresses = <&iris 0x0 0x0 0x0 0x25800000>;
+ };
};
smp2p-adsp {
@@ -5399,7 +5410,7 @@ &config_noc SLAVE_VENUS_CFG QCOM_ICC_TAG_ACTIVE_ONLY>,
interconnect-names = "cpu-cfg",
"video-mem";
- memory-region = <&video_mem>;
+ memory-region = <&video_mem>, <&iris_iova>;
resets = <&gcc GCC_VIDEO_AXI0_CLK_ARES>;
reset-names = "bus";
--
2.34.1