Re: [PATCH 1/1] mmc: sdhci-esdhc-imx: Use pinctrl PM helpers

[Mirza Krak <mirza.krak@hostmobility.com>]

2015-06-16 11:05 GMT+02:00 Stefan Agner <stefan@agner.ch>:
> The pltfm_suspend/resume functions have been used since quite some time.
> However, the Toradex branch carries a patch which introduces local
> suspend/resume functions to work around a system PM vs. runtime PM
> suspend issue.

Hence my confusion :).

> > I am thinking sdhci_suspend_host would be good location, but then the
> > change will effect a lot more drivers. Maybe a good thing?
>
> I guess most device trees don't have a specific idle/sleep state
> specification, how does the pinctrl API act in this situation?

pinctrl API can handle if states are not defined. Also the API calls
are considered successful when successfully set state or if no state
definition is present.

Undefined states are set to ERR_PTR(-ENODEV)

and in the API calls there is a

if (IS_ERR(state))
    return 0; /* No such state */

>
> FWIW, the Vybrid SoC is not able to control pins during LPSTOP suspend,
> hence configuring the sleep mode explicitly for system PM is not very
> useful on that platform. However, for runtime PM it coud still be
> valuable I guess.

I was testing the "standby" state and noticed unwanted states on some
pins and hence this patch :). Good to know about LPSTOP.

-- 
Med Vänliga Hälsningar / Best Regards

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Mirza Krak
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