On 08/08/2013 07:01 PM, Mark Brown wrote:
> * PGP Signed by an unknown key
>
> On Thu, Aug 08, 2013 at 02:56:29PM +0800, Wei Ni wrote:
>
>> + mutex_lock(&data->update_lock);
>> +
>> + if (is_enable)
>> + ret = regulator_enable(data->lm90_reg);
>> + else
>> + ret = regulator_disable(data->lm90_reg);
>> +
>> + if (ret < 0)
>> + dev_err(&client->dev,
>> + "Error in %s rail vdd, error %d\n",
>> + (is_enable) ? "enabling" : "disabling", ret);
>> + else
>> + dev_info(&client->dev, "success in %s rail vdd\n",
>> + (is_enable) ? "enabling" : "disabling");
>> +
>> + mutex_unlock(&data->update_lock);
>
> Two things here. One is that it's not clear what this lokc is
> protecting since the only thing in the locked region is the regulator
> operation and that is thread safe. The other thing is that I'm not
> seeing anthing that ensures that enables and disables are matched -
> regulators are reference counted so two enables need two disables.
>
>> + data->lm90_reg = regulator_get(&client->dev, "vdd");
>> + if (IS_ERR_OR_NULL(data->lm90_reg)) {
>
> NULL is a valid regulator, use IS_ERR().
>
>> + if (PTR_ERR(data->lm90_reg) == -ENODEV)
>> + dev_info(&client->dev,
>> + "No regulator found for vdd. Assuming vdd is always powered.");
>> + else
>> + dev_warn(&client->dev,
>> + "Error [%ld] in getting the regulator handle for vdd.\n",
>> + PTR_ERR(data->lm90_reg));
>
> You shouldn't just be ignoring errors here, though there are deployment
> difficulties with making sure a stub regulator is provided. These
> should be getting easier after the next merge window, the stubs will be
> being tweaked slightly to have an "assume it's there" option even when
Oh, really, could you show me the patch, I wish to take a look :)
Wei.
> regulators are used. Especially in cases with device tree you should be
> paying attention to -EPROBE_DEFER, that will accurately reflect if a
> regulator is present but not loaded yet.
>
> That said if you *are* going to do this you should request the
> regulator using devm_regulator_get_optional(), this is intended to
> support things that don't need regulators (though that's not the case
> here).
>
> * Unknown Key
> * 0x7EA229BD
>
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