[PATCH v5] iommu/arm-smmu-qcom: add actlr settings for mdss on Qualcomm platforms

Will Deacon will at kernel.org
Fri Jan 9 03:52:54 PST 2026


On Fri, Jan 09, 2026 at 04:59:13PM +0530, Bibek Kumar Patro wrote:
> 
> 
> On 1/6/2026 4:28 AM, Will Deacon wrote:
> > On Tue, 09 Dec 2025 10:53:23 +0530, bibek.patro at oss.qualcomm.com wrote:
> > > Add ACTLR settings for missing MDSS devices on Qualcomm platforms.
> > > 
> > > These are QoS settings and are specific to per SoC thus different
> > > settings, eg: some have shallow prefetch while others have no
> > > prefetch.
> > > 
> > > Aswell, this prefetch feature is not implemented for all the
> > > platforms, capturing to those are implemented to the best of my
> > > knowledge.
> > > 
> > > [...]
> > 
> > Applied to iommu (arm/smmu/updates), thanks!
> > 
> 
> Hi Will,
> 
> While reviewing the applied patch, I noticed that during the transition from
> v2 [1] to v3 [2], one of the SoC entries (sa8775p) appears to have been
> dropped while addressing the review comments.
> 
> Sorry for not catching this earlier.
> 
> Would it be acceptable at this stage to send a v6 including the diff below?
> Alternatively, if it’s easier on your side, please feel free to squash this
> into the existing patch currently applied in your tree.
> 
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> index 456d5146831e..718d102356d9 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
> @@ -43,6 +43,8 @@ static const struct of_device_id
> qcom_smmu_actlr_client_of_match[] = {
>                         .data = (const void *) (PREFETCH_DEEP | CPRE |
> CMTLB) },
>         { .compatible = "qcom,qcm2290-mdss",
>                         .data = (const void *) (PREFETCH_SHALLOW | CPRE |
> CMTLB) },
> +       { .compatible = "qcom,sa8775p-mdss",
> +                       .data = (const void *) (PREFETCH_DEFAULT | CMTLB) },
>         { .compatible = "qcom,sc7280-mdss",
>                         .data = (const void *) (PREFETCH_SHALLOW | CPRE |
> CMTLB) },
>         { .compatible = "qcom,sc7280-venus",
> 
> If neither approach looks suitable, I can send a standalone follow‑up patch,
> either on top of your tree[3] or on tip.

No worries, but please just send a patch on top so that we have an
explanation in the commit message and we won't have to rebase the
branch.

Cheers,

Will



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