Re: [PATCH v5 0/6] iommu/arm-smmu: Add runtime pm/sleep support

[Vivek Gautam]

On 01/09/2018 04:53 PM, Rafael J. Wysocki wrote:
> On Tuesday, January 9, 2018 11:01:43 AM CET Vivek Gautam wrote:
> > This series provides the support for turning on the arm-smmu's
> > clocks/power domains using runtime pm. This is done using the
> > recently introduced device links patches, which lets the smmu's
> > runtime to follow the master's runtime pm, so the smmu remains
> > powered only when the masters use it.
> >
> > It also adds support for Qcom's arm-smmu-v2 variant that
> > has different clocks and power requirements.
> >
> > Took some reference from the exynos runtime patches [2].
> >
> > Previous version of the patchset [1].
> >
> > After much discussion [4] over the use of pm_runtime_get/put() in
> > .unmap op path for the arm-smmu, and after disussing over more than
> > a couple of approaches to address this, we are putting forward the
> > changes *without* using pm_runtime APIs in 'unmap'. Rather, letting
> > the client device take the control of powering on/off the connected
> > iommu through pm_runtime_get(put)_suppliers() APIs for the scnerios
> > when the iommu power can't be directly controlled by clients through
> > device links.
> > Rafael has agreed to export the suppliers APIs [5].
> >
> > [V5]
> >     * Dropped runtime pm calls from "arm_smmu_unmap" op as discussed over
> >       the list [4] for the last patch series.
> >     * Added a patch to export pm_runtime_get/put_suppliers() APIs to the
> >       series as agreed with Rafael [5].
> >     * Added the related patch for msm drm iommu layer to use
> >       pm_runtime_get/put_suppliers() APIs in msm_mmu_funcs.
> >     * Dropped arm-mmu500 clock patch since that would break existing
> >       platforms.
> >     * Changed compatible 'qcom,msm8996-smmu-v2' to 'qcom,smmu-v2' to reflect
> >       the IP version rather than the platform on which it is used.
> >       The same IP is used across multiple platforms including msm8996,
> >       and sdm845 etc.
> >     * Using clock bulk APIs to handle the clocks available to the IP as
> >       suggested by Stephen Boyd.
> >     * The first patch in v4 version of the patch-series:
> >       ("iommu/arm-smmu: Fix the error path in arm_smmu_add_device") has
> >       already made it to mainline.
> >
> > [V4]
> >     * Reworked the clock handling part. We now take clock names as data
> >       in the driver for supported compatible versions, and loop over them
> >       to get, enable, and disable the clocks.
> >     * Using qcom,msm8996 based compatibles for bindings instead of a generic
> >       qcom compatible.
> >     * Refactor MMU500 patch to just add the necessary clock names data and
> >       corresponding bindings.
> >     * Added the pm_runtime_get/put() calls in .unmap iommu op (fix added by
> >       Stanimir on top of previous patch version.
> >     * Added a patch to fix error path in arm_smmu_add_device()
> >     * Removed patch 3/5 of V3 patch series that added qcom,smmu-v2 bindings.
> >
> > [V3]
> >     * Reworked the patches to keep the clocks init/enabling function
> >       separately for each compatible.
> >
> >     * Added clocks bindings for MMU40x/500.
> >
> >     * Added a new compatible for qcom,smmu-v2 implementation and
> >       the clock bindings for the same.
> >
> >     * Rebased on top of 4.11-rc1
> >
> > [V2]
> >     * Split the patches little differently.
> >
> >     * Addressed comments.
> >
> >     * Removed the patch #4 [3] from previous post
> >       for arm-smmu context save restore. Planning to
> >       post this separately after reworking/addressing Robin's
> >       feedback.
> >
> >     * Reversed the sequence to disable clocks than enabling.
> >       This was required for those cases where the
> >       clocks are populated in a dependent order from DT.
> >
> > [1] https://www.spinics.net/lists/arm-kernel/msg567488.html
> > [2] https://lkml.org/lkml/2016/10/20/70
> > [3] https://patchwork.kernel.org/patch/9389717/
> > [4] https://patchwork.kernel.org/patch/9827825/
> > [5] https://patchwork.kernel.org/patch/10102445/
> >
> > Sricharan R (3):
> >    iommu/arm-smmu: Add pm_runtime/sleep ops
> >    iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device
> >    iommu/arm-smmu: Add the device_link between masters and smmu
> >
> > Vivek Gautam (3):
> >    base: power: runtime: Export pm_runtime_get/put_suppliers
> >    iommu/arm-smmu: Add support for qcom,smmu-v2 variant
> >    drm/msm: iommu: Replace runtime calls with runtime suppliers
> >
> >   .../devicetree/bindings/iommu/arm,smmu.txt         |  35 ++++++
> >   drivers/base/power/runtime.c                       |   2 +
> >   drivers/gpu/drm/msm/msm_iommu.c                    |  16 +--
> >   drivers/iommu/arm-smmu.c                           | 124 ++++++++++++++++++++-
> >   4 files changed, 163 insertions(+), 14 deletions(-)
> I need some time to review the series.

Sure, thanks Rafael.

regards
Vivek

> Thanks,
> Rafael
>
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