Re: [PATCH] sdhci: Forward EPROBE_DEFER on vmmc and vqmmc regulators

[Mike Looijmans]

On 26-3-2014 16:09, Georgi Djakov wrote:
> On 03/07/2014 04:18 PM, Mike Looijmans wrote:
> > If vmmc or vqmmc regulators are controlled by an I2C device, the
> > request for the regulator is likely to fail because the I2C bus has
> > not been probed yet. The sdhci then incorrectly assumes that the user
> > never wanted to use a regulator anyway and continues without ever
> > enabling or configuring the required regulator.
> >
> > To solve this, when a required voltage regulator returns
> > EPROBE_DEFER, signalling that the regulator exists but is not
> > available yet, forward this error to the probe method instead
> > of simply assuming that the user never wanted to use a regulator
> > anyway.
> >
> > Tested on a custom board that has an I2C regulator for one of the sdhcis
> > and no regulators at all for the other. This patch enables such a system
> > to work correctly.
> > ---
> >   drivers/mmc/host/sdhci.c |    8 ++++++--
> >   1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> > index 34aef81..43b90c1 100644
> > --- a/drivers/mmc/host/sdhci.c
> > +++ b/drivers/mmc/host/sdhci.c
> > @@ -2972,6 +2972,8 @@ int sdhci_add_host(struct sdhci_host *host)
> >       host->vqmmc = regulator_get_optional(mmc_dev(mmc), "vqmmc");
> >       if (IS_ERR_OR_NULL(host->vqmmc)) {
> >           if (PTR_ERR(host->vqmmc) < 0) {
> > +            if (PTR_ERR(host->vqmmc) == -EPROBE_DEFER)
> > +                return -EPROBE_DEFER;
> >               pr_info("%s: no vqmmc regulator found\n",
> >                   mmc_hostname(mmc));
> >               host->vqmmc = NULL;
> > @@ -3048,8 +3050,10 @@ int sdhci_add_host(struct sdhci_host *host)
> >       host->vmmc = regulator_get_optional(mmc_dev(mmc), "vmmc");
> >       if (IS_ERR_OR_NULL(host->vmmc)) {
> >           if (PTR_ERR(host->vmmc) < 0) {
> > -            pr_info("%s: no vmmc regulator found\n",
> > -                mmc_hostname(mmc));
> > +            if (PTR_ERR(host->vmmc) == -EPROBE_DEFER)
> > +                return -EPROBE_DEFER;
> > +            pr_info("%s: no vmmc regulator found (%d)\n",
>
> I suggest using %ld here. The rest looks fine to me! Thanks!

Does this mean you're waiting for a patch v2 that I should submit?

> > +                mmc_hostname(mmc), PTR_ERR(host->vmmc));
> >               host->vmmc = NULL;
> >           }
> >       }
>
> BR,
> Georgi


--
Mike Looijmans
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