[01/17] mmc: host: omap_hsmmc: use devm_regulator_get_optional() for vmmc
diff mbox

Message ID 1438168187-1614-2-git-send-email-kishon@ti.com
State New
Headers show

Commit Message

Kishon Vijay Abraham I July 29, 2015, 11:09 a.m. UTC
Since vmmc can be optional for some platforms, use
devm_regulator_get_optional() for vmmc. Now return error only
in the case of -EPROBE_DEFER and for all other cases set
host->vcc to NULL.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 drivers/mmc/host/omap_hsmmc.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

Comments

Grygorii Strashko July 29, 2015, 12:09 p.m. UTC | #1
On 07/29/2015 02:09 PM, Kishon Vijay Abraham I wrote:
> Since vmmc can be optional for some platforms, use
> devm_regulator_get_optional() for vmmc. Now return error only
> in the case of -EPROBE_DEFER and for all other cases set
> host->vcc to NULL.
> 
> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
> ---
>   drivers/mmc/host/omap_hsmmc.c |    8 +++++---
>   1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index 4d12032..b673e59 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -344,11 +344,13 @@ static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host)
>   	struct regulator *reg;
>   	int ocr_value = 0;
>   
> -	reg = devm_regulator_get(host->dev, "vmmc");
> +	reg = devm_regulator_get_optional(host->dev, "vmmc");
>   	if (IS_ERR(reg)) {
> -		dev_err(host->dev, "unable to get vmmc regulator %ld\n",
> +		if (PTR_ERR(reg) == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +		host->vcc = NULL;
> +		dev_dbg(host->dev, "unable to get vmmc regulator %ld\n",
>   			PTR_ERR(reg));
> -		return PTR_ERR(reg);

I think, It could be unsafe to just drop this return.
regulator_get_optional may return:
1 valid pointer on regulator : success;
2 ERR_PTR(-ENODEV)           : regulator is not assigned, can proceed.
3 ERR_PTR(-EPROBE_DEFER)     : regulator is assigned, but not ready yet, retry.
4 ERR_PTR(<other error codes>: regulator is assigned, but can't be retrieved, failure, can't proceed

So, It's allowed to continue with host->vcc = NULL; only in case [2], while
in case [4] probe should fail.

>   	} else {
>   		host->vcc = reg;
>   		ocr_value = mmc_regulator_get_ocrmask(reg);
>
Kishon Vijay Abraham I July 31, 2015, 3:29 p.m. UTC | #2
Hi Grygorii,

On Wednesday 29 July 2015 05:39 PM, Grygorii Strashko wrote:
> On 07/29/2015 02:09 PM, Kishon Vijay Abraham I wrote:
>> Since vmmc can be optional for some platforms, use
>> devm_regulator_get_optional() for vmmc. Now return error only
>> in the case of -EPROBE_DEFER and for all other cases set
>> host->vcc to NULL.
>>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
>> ---
>>   drivers/mmc/host/omap_hsmmc.c |    8 +++++---
>>   1 file changed, 5 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
>> index 4d12032..b673e59 100644
>> --- a/drivers/mmc/host/omap_hsmmc.c
>> +++ b/drivers/mmc/host/omap_hsmmc.c
>> @@ -344,11 +344,13 @@ static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host)
>>   	struct regulator *reg;
>>   	int ocr_value = 0;
>>   
>> -	reg = devm_regulator_get(host->dev, "vmmc");
>> +	reg = devm_regulator_get_optional(host->dev, "vmmc");
>>   	if (IS_ERR(reg)) {
>> -		dev_err(host->dev, "unable to get vmmc regulator %ld\n",
>> +		if (PTR_ERR(reg) == -EPROBE_DEFER)
>> +			return -EPROBE_DEFER;
>> +		host->vcc = NULL;
>> +		dev_dbg(host->dev, "unable to get vmmc regulator %ld\n",
>>   			PTR_ERR(reg));
>> -		return PTR_ERR(reg);
> 
> I think, It could be unsafe to just drop this return.
> regulator_get_optional may return:
> 1 valid pointer on regulator : success;
> 2 ERR_PTR(-ENODEV)           : regulator is not assigned, can proceed.
> 3 ERR_PTR(-EPROBE_DEFER)     : regulator is assigned, but not ready yet, retry.
> 4 ERR_PTR(<other error codes>: regulator is assigned, but can't be retrieved, failure, can't proceed
> 
> So, It's allowed to continue with host->vcc = NULL; only in case [2], while
> in case [4] probe should fail.

You are right. Will fix it and resend the patch.

Thanks
Kishon
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Patch
diff mbox

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 4d12032..b673e59 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -344,11 +344,13 @@  static int omap_hsmmc_reg_get(struct omap_hsmmc_host *host)
 	struct regulator *reg;
 	int ocr_value = 0;
 
-	reg = devm_regulator_get(host->dev, "vmmc");
+	reg = devm_regulator_get_optional(host->dev, "vmmc");
 	if (IS_ERR(reg)) {
-		dev_err(host->dev, "unable to get vmmc regulator %ld\n",
+		if (PTR_ERR(reg) == -EPROBE_DEFER)
+			return -EPROBE_DEFER;
+		host->vcc = NULL;
+		dev_dbg(host->dev, "unable to get vmmc regulator %ld\n",
 			PTR_ERR(reg));
-		return PTR_ERR(reg);
 	} else {
 		host->vcc = reg;
 		ocr_value = mmc_regulator_get_ocrmask(reg);