Re: [PATCH 2/9] regulator: helper routine to extract regulator_init_data

Russell King - ARM Linux
2011-10-04T23:01:59Z

On Tue, Sep 27, 2011 at 01:10:04PM +0100, Mark Brown wrote:
> On Tue, Sep 27, 2011 at 03:42:45PM +0530, Rajendra Nayak wrote:
>
> > + init_data = devm_kzalloc(dev, sizeof(struct regulator_init_data),
> > + GFP_KERNEL);
> > + if (!init_data)
> > + return NULL; /* Out of memory? */
>
> This means that the init data will be kept around for the entire
> lifetime of the device rather than being discarded.

May I remind you that devm_* lifetime expires whenever the associated
driver is unbound, which can be much shorter than the lifetime of the
struct device.

It expires when any of the following occurs:
1. userspace asks the associated driver to be unbound
2. the driver is removed
3. any driver probe for this struct device fails
4. the struct device is unregistered.

So: don't use devm_* for anything other than stuff inside a driver being
associated with the struct device itself. Other uses are a bug waiting
to happen.