On Sep 14 2016 or thereabouts, Brian Norris wrote: > On Wed, Sep 14, 2016 at 03:55:05PM +0800, Brian Norris wrote: > > The default behavior of regulator_get() is to provide a dummy regulator > > if none is found. So the pointer is never NULL, and it won't break > > devices without a regulator. If you don't want a dummy regulator you > > would use regulator_get_optional() instead, and you would then need to > > handle ERR_PTR(-ENODEV) specifically. > > One caveat to the never-NULL comment above that I just noticed: > > If CONFIG_REGULATOR=n, then regulator_get() actually returns NULL (see > include/linux/regulator/consumer.h), but it also specifically has a > comment right next to that NULL return, saying: > > /* Nothing except the stubbed out regulator API should be > * looking at the value except to check if it is an error > * value. Drivers are free to handle NULL specifically by > * skipping all regulator API calls, but they don't have to. > * Drivers which don't, should make sure they properly handle > * corner cases of the API, such as regulator_get_voltage() > * returning 0. > */ > > So, we still don't need to handle the NULL case specially. Well, all the other regulator calls are either regulator_enable() or regulator_disable(), which in this case (CONFIG_REGULATOR=n) are returning 0. So I think the whole patch is safe in its current form. Thanks for the explanations. Acked-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx> Cheers, Benjamin > > Brian -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html