From mboxrd@z Thu Jan  1 00:00:00 1970
From: joe@perches.com (Joe Perches)
Date: Wed, 02 Sep 2015 08:07:56 -0700
Subject: [PATCH 2/2] mmc: sdhci-pxav3: Print ret value on error from
 sdhci_add_host() fn
In-Reply-To: <55E6F497.8080300@linaro.org>
References: <1441135454-6902-1-git-send-email-vaibhav.hiremath@linaro.org>
 <1441135454-6902-3-git-send-email-vaibhav.hiremath@linaro.org>
 <1441139838.12163.5.camel@perches.com> <55E6F497.8080300@linaro.org>
Message-ID: <1441206476.12163.44.camel@perches.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

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
and perhaps should be at pr_notice/KERN_NOTICE

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

If it's moderately common, that message should likely
be ratelimited if it exists at all.