Re: [PATCH V2] regulator: fixed: update to devm_* API

From: Manish Badarkhe
Date: Tue Jan 28 2014 - 04:01:43 EST


On Tue, Jan 28, 2014 at 2:25 PM, Heiko Stübner <heiko@xxxxxxxxx> wrote:
> On Tuesday, 28. January 2014 14:16:39 Manish Badarkhe wrote:
>> Hi Heiko
>>
>> Thank you for your reply.
>>
>> On Tue, Jan 28, 2014 at 1:08 PM, Heiko Stübner <heiko@xxxxxxxxx> wrote:
>> > On Tuesday, 28. January 2014 12:46:01 Manish Badarkhe wrote:
>> >> Hi Dmitry,
>> >>
>> >> Thank you for your review.
>> >>
>> >> On Tue, Jan 28, 2014 at 12:03 PM, Dmitry Torokhov
>> >>
>> >> <dmitry.torokhov@xxxxxxxxx> wrote:
>> >> > Hi Manish,
>> >> >
>> >> > On Tue, Jan 28, 2014 at 08:42:00AM +0530, Manish Badarkhe wrote:
>> >> >> Update the code to use devm_* API so that driver core will manage
>> >> >> resources.
>> >> >>
>> >> >> Signed-off-by: Manish Badarkhe <badarkhe.manish@xxxxxxxxx>
>> >> >> ---
>> >> >> Changes since V1:
>> >> >> 1. Updated driver to use "devm_kzalloc" to "kstrdup".
>> >> >> 2. Updated commit message.
>> >> >>
>> >> >> Not tested on any board.
>> >> >>
>> >> >> :100644 100644 5ea64b9... e9763a4... M
>> >> >> :drivers/regulator/fixed.c
>> >> >> :
>> >> >> drivers/regulator/fixed.c | 42
>> >> >> ++++++++++++------------------------------
>> >> >> 1 file changed, 12 insertions(+), 30 deletions(-)
>> >> >>
>> >> >> diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
>> >> >> index 5ea64b9..e9763a4 100644
>> >> >> --- a/drivers/regulator/fixed.c
>> >> >> +++ b/drivers/regulator/fixed.c
>> >> >> @@ -132,15 +132,15 @@ static int reg_fixed_voltage_probe(struct
>> >> >> platform_device *pdev)>>
>> >> >>
>> >> >> GFP_KERNEL);
>> >> >>
>> >> >> if (drvdata == NULL) {
>> >> >>
>> >> >> dev_err(&pdev->dev, "Failed to allocate device data\n");
>> >> >>
>> >> >> - ret = -ENOMEM;
>> >> >> - goto err;
>> >> >> + return -ENOMEM;
>> >> >>
>> >> >> }
>> >> >>
>> >> >> - drvdata->desc.name = kstrdup(config->supply_name, GFP_KERNEL);
>> >> >> + drvdata->desc.name = devm_kzalloc(&pdev->dev,
>> >> >> + strlen(config->supply_name) +
>> >> >> 1,
>> >> >> + GFP_KERNEL);
>> >> >>
>> >> >> if (drvdata->desc.name == NULL) {
>> >> >>
>> >> >> dev_err(&pdev->dev, "Failed to allocate supply name\n");
>> >> >>
>> >> >> - ret = -ENOMEM;
>> >> >> - goto err;
>> >> >> + return -ENOMEM;
>> >> >>
>> >> >> }
>> >> >
>> >> > Umm, I am fairly certain that devm_kzalloc() can't be used as a
>> >> > substitute for kstrdup, at least not without accompanying memcpy.
>> >>
>> >> Yes, I have provided allocation but it should be followed with
>> >> assignment.
>> >> Can I modify like this,
>> >>
>> >> + drvdata->desc.name = devm_kzalloc(&pdev->dev,
>> >> + strlen(config->supply_name) + 1,
>> >> + GFP_KERNEL);
>> >> + if (drvdata->desc.name)
>> >> + sprintf(drvdata->desc.name, "%s", config->supply_name);
>> >
>> > hmm, so you replaced a general helper function by open coding the string-
>> > duplication. Doesn't this defeat the target of simplifying the code?
>>
>> Intention here, is to use devm_ API and to adopt this I have to do these
>> modifications for "kstrdup" functions. I have seen in regulator folder
>> almost all drivers adopted to "devm_" API. Hence same thing I am following
>> to update this driver. Please let me know whether to go ahead with this
>> patch or retain driver as it is.
>
> I don't have a strong opinion on this and others are most likely more qualified
> to have a definitive answer, I just found it strange to exchange one open-coded
> pattern against another open-coded one.
>
> So don't let me keep you from it ;-)

Okay.
@Mark, Dmitry: Please let me know your opinion on this.

Thanks
Manish Badarkhe
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