[PATCH 08/22] arm64: dts: qcom: sm8350: Reserve low IOVA range for Iris
From: Vikash Garodia
Date: Fri Aug 07 2026 - 04:27:57 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: a2b0c5eba743 ("arm64: dts: qcom: sm8350: add Iris device")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
---
arch/arm64/boot/dts/qcom/sm8350.dtsi | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/boot/dts/qcom/sm8350.dtsi b/arch/arm64/boot/dts/qcom/sm8350.dtsi
index 32b47f5ec1f6755dfe9eb92df9c03e5fc2c992bb..b376dda0ed5208633660cc3b975cee738134b758 100644
--- a/arch/arm64/boot/dts/qcom/sm8350.dtsi
+++ b/arch/arm64/boot/dts/qcom/sm8350.dtsi
@@ -553,6 +553,17 @@ removed_mem: memory@d8800000 {
reg = <0x0 0xd8800000 0x0 0x6800000>;
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 {
@@ -2786,7 +2797,7 @@ &config_noc SLAVE_VENUS_CFG QCOM_ICC_TAG_ACTIVE_ONLY>,
operating-points-v2 = <&iris_opp_table>;
iommus = <&apps_smmu 0x2100 0x400>;
- memory-region = <&pil_video_mem>;
+ memory-region = <&pil_video_mem>, <&iris_iova>;
status = "disabled";
--
2.34.1