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

[Vivek Gautam <vivek.gautam@codeaurora.org>]

Hi Tomasz,


On 3/5/2018 6:55 PM, Tomasz Figa wrote:
> Hi Vivek,
>
> On Fri, Mar 2, 2018 at 7:10 PM, Vivek Gautam
> <vivek.gautam@codeaurora.org> 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.

Sure. I will be sending a patch, based on this series, to add 
'qcom,smmu-500'
that enables *rpm_suported* flag for us.
We can try to take care of some of the things with that.
> Reviewed-by: Tomasz Figa <tfiga@chromium.org>

Thanks for the review.

regards
Vivek
>
> Best regards,
> Tomasz