Re: [PATCH 1/3] iommu/qcom: Invalidate the TLB in flush_iotlb_all

From: Konrad Dybcio

Date: Mon Nov 02 2026 - 04:55:26 EST


On 10/30/26 11:04 PM, Dmitry Baryshkov wrote:
> qcom_iommu_flush_iotlb_all() only waits for a TLB sync and never
> invalidates anything. iommu_unmap() users do not notice, since
> io-pgtable invalidates each page through the gather, but drm/msm unmaps
> with a NULL gather and relies on flush_iotlb_all. On db410c the GPU then
> hangs on stale TLB entries as soon as another process reuses the IOVAs.
>
> Invalidate the whole context, as arm-smmu does, and keep iotlb_sync a
> plain sync.
>
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxxxxxxxx>
> ---

Acked-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx>

Konrad