[PATCH v3 1/2] Documentation: mmc: sdhci-of-arasan: add description of power domain

Ulf Hansson ulf.hansson at linaro.org
Thu Sep 22 00:14:03 PDT 2016


On 20 September 2016 at 04:29, Ziyuan Xu <xzy.xu at rock-chips.com> wrote:
> hi Ulf,
>
>
> On 2016年09月17日 16:49, Ulf Hansson wrote:
>>
>> On 17 September 2016 at 04:32, Ziyuan Xu <xzy.xu at rock-chips.com> wrote:
>>>
>>> Add power domain as a optional property for sdhci-of-arasan, which can
>>> be turned off in the so-called unused condition, such as suspend and
>>> remove. Aim to lower power requirements.
>>
>> I assume runtime suspend make sense as well?
>
>
> Sorry to reply this mail after a long time.
>
> On rk3399 platform, there is a eMMC-phy which is in charge of eMMC's logic
> interface. We should guarantee that phy is ready before cmd/data transfer.
> I mean that I need to consider about the resume latency, so that I can land
> RPM for arasan-of-sdhci.
> I intend to use auto-suspend for arasan-of-sdhci.
>

Okay!

>>
>> Moreover, perhaps you could share a little information here about what
>> needs to be done at the driver level which controls the mmc IP. More
>> precisely, what do you need to do at runtime_suspend, suspend,
>> runtime_resume, and resume?
>
>
> Invoke sdhci_runtime_suspend_host, disable relevant clock in
> rumtime_suspend, deprocessing in runtime_resume.
> Is that ok?

Okay!

[...]

Thanks for sharing some more information, could you please re-spin
with an updated change log?

Kind regards
Uffe



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