Messages in this thread | | | From | Pramod Gurav <> | Date | Fri, 23 Sep 2016 11:56:48 +0530 | Subject | Re: [PATCH v3] mmc: sdhci-msm: Add pm_runtime and system PM support |
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Hi Ritesh,
Thanks for the inputs.
On 22 September 2016 at 20:02, Ritesh Harjani <riteshh@codeaurora.org> wrote: > Hi Pramod,
<snip>
>> Thanks Ulf for the comments. Will check this and see if there is >> something of this sort we have to do to achieve auto tuning. >> Adding Ritesh who has been posting some SDHCI MSM patches recently in >> case he knows about this. > > > Internally, we don't use this Auto re-tuning and rely on explicit re-tune by > host driver. > > Question though - > 1. why do we need to call sdhci_runtime_resume/suspend from > sdhci_msm_runtime_suspend/resume? > From what I see is, sdhci_runtime_susend/resume will do reset and re-program > of host->pwr and host->clk because of which a retune will be required for > the next command after runtime resume.
Honestly I took reference from existing SDHCI HC driver which implement the runtime PM and each one uses this function.
> > We can *only* disable and enable the clocks in > sdhci_msm_runtime_suspend/resume? > Thoughts? With this, I suppose you would not see any issue. This should work as I did not have this funtion call in my V1 but later included when I referred the other sdhci drivers.
> > > Though for this issue, since internally also auto retuning is never used, we > can have this mode disabled. I can once again check with HW team to get more > details about this mode for MSM controller. This seems a read only register. And I could not find any other reference of this mode in any of the docs. > >> >> Regards, >> Pramod >> >
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