Re: [PATCH 2/2] mmc: sdhci-pxav3: Print ret value on error from sdhci_add_host() fn

[Vaibhav Hiremath]

On Wednesday 02 September 2015 08:37 PM, Joe Perches wrote:
> On Wed, 2015-09-02 at 18:37 +0530, Vaibhav Hiremath wrote:
> > On Wednesday 02 September 2015 02:07 AM, Joe Perches wrote:
> > > On Wed, 2015-09-02 at 00:54 +0530, Vaibhav Hiremath wrote:
> > > > Return value would give clear information about the actual root-cause
> > > > of the failure.
> > > > diff --git a/drivers/mmc/host/sdhci-pxav3.c b/drivers/mmc/host/sdhci-pxav3.c
> > > > @@ -455,7 +455,7 @@ static int sdhci_pxav3_probe(struct platform_device *pdev)
> > > >
> > > >    	ret = sdhci_add_host(host);
> > > >    	if (ret) {
> > > > -		dev_err(&pdev->dev, "failed to add host\n");
> > > > +		dev_err(&pdev->dev, "failed to add host ret - %d\n", ret);
> > > >    		goto err_add_host;
> > > >    	}
> > >
> > > If this is really desirable, there are many other callers of
> > > sdhci_add_host with error messages just like this one.
> > How about this? If you are ok, I can change it and submit the patch
> > again.
> > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> []
> > @@ -3176,8 +3176,11 @@ int sdhci_add_host(struct sdhci_host *host)
> >                   mmc->caps |= MMC_CAP_NEEDS_POLL;
> >
> >           /* If there are external regulators, get them */
> > -       if (mmc_regulator_get_supply(mmc) == -EPROBE_DEFER)
> > +       if (mmc_regulator_get_supply(mmc) == -EPROBE_DEFER) {
> > +               pr_err("%s: regulator supply unavailable, deferring
> > probe. \n",
> > +                               mmc_hostname(mmc));
> >                   return -EPROBE_DEFER;
> > +       }
>
> (your email client has inappropriate line wrapping)
>
> The KERN_<LEVEL> here probably isn't right.
>
> Deferring isn't an error, at best it's a notification

I would consider it as an ERROR if it gets deferred
continuously/multiple times due to same reason.

> and perhaps should be at pr_notice/KERN_NOTICE

Yeah, KERN_NOTICE looks right here.

> I don't know how often or how many times this deferral
> can occur.  Do you?

-EDEFER_PROBE usually means that driver has some dependency,
for which it has to wait.
In my case, during every boot, I pxav3_sdhci_probe gets deferred once
due to regulator unavailability.

Thanks,
Vaibhav
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