Re: [PATCH v8 0/5] iommu/arm-smmu: Add runtime pm/sleep support

[Tomasz Figa]

Hi Vivek,

On Fri, Mar 2, 2018 at 7:10 PM, Vivek Gautam
<vivek.gautam@xxxxxxxxxxxxxx> 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 [1].
>
> After another round of discussion [3], we now finally seem to be
> in agreement to add a flag based on compatible, a flag that would
> indicate if a particular implementation of arm-smmu supports
> runtime pm or not.
> This lets us to use the much-argued pm_runtime_get_sync/put_sync()
> calls in map/unmap callbacks so that the clients do not have to
> worry about handling any of the arm-smmu's power.
> The patch that exported couple of pm_runtime suppliers APIS, viz.
> pm_runtime_get_suppliers(), and pm_runtime_put_suppliers() can be
> dropped since we don't have a user now for these APIs.
> Thanks Rafael for reviewing the changes, but looks like we don't
> need to export those APIs for some more time. :)
>
> Previous version of this patch series is @ [5].

Thanks for addressing my comments. There is still a bit of space for
improving the granularity of power management, as far as I understood
how it works on SDM845 correctly, but as a first step, this should at
least let things work.

Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>

Best regards,
Tomasz