Re: [PATCH v3 4/4] arm64: dts: qcom: qcs615: add the APPS SMMU node
From: Qingqing Zhou <hidden>
Date: 2024-10-30 08:22:11
Also in:
linux-arm-msm, linux-iommu, lkml
在 10/28/2024 11:46 PM, Konrad Dybcio 写道:
On 26.10.2024 8:18 PM, Dmitry Baryshkov wrote:quoted
On Fri, Oct 25, 2024 at 06:45:01PM +0200, Konrad Dybcio wrote:quoted
On 25.10.2024 1:06 PM, Dmitry Baryshkov wrote:quoted
On Fri, Oct 25, 2024 at 10:54:24AM +0200, Konrad Dybcio wrote:quoted
On 25.10.2024 5:07 AM, Qingqing Zhou wrote:quoted
Add the APPS SMMU node for QCS615 platform. Add the dma-ranges to limit DMA address range to 36bit width to align with system architecture. Signed-off-by: Qingqing Zhou <redacted> ---You probably also want to mark it `dma-coherent` (see e.g. x1e80100.dtsi)Is it? I don't think SM6150 had dma-coherent SMMU, at least it wasn't marked as such.I don't think I have any documentation on this, so.. one way to find out!I don't have qcs615 at hand, so a purely theoretical question. But how should it break if we mark it as dma-coherent, while it is not?The board will hang rather quickly Konrad
Thanks for review comments from Konrad and Dmitry! QCS615 SMMU hardware supports IO-coherency after confirming with Qualcomm hardware team. We also try to add "dma-coherent" for APPS SMMU node and test some SMMU clients, such as UFS and Ethernet, these SMMU clients work well on QCS615. Do you advise and agree to add "dma-coherent" for SMMU node?