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

From: Vaibhav Hiremath
Date: Wed Sep 02 2015 - 11:17:03 EST

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
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));
+ }

(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.

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