Messages in this thread | | | Subject | Re: [PATCH 1/5] regulator: core: Resolve supply earlier | From | Jon Hunter <> | Date | Tue, 19 Apr 2016 17:09:59 +0100 |
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On 19/04/16 16:40, Mark Brown wrote: > * PGP Signed by an unknown key > > On Tue, Apr 19, 2016 at 11:16:59AM +0100, Jon Hunter wrote: > >> So the following seems to work, but only item I am uncertain about >> is if it is ok to move the mutex_lock to after the >> machine_set_constraints()? > > We definitely don't need the list to apply constraints to a single > regulator. > >> + mutex_lock(®ulator_list_mutex); >> + >> ret = device_register(&rdev->dev); >> if (ret != 0) { >> put_device(&rdev->dev); >> + mutex_unlock(®ulator_list_mutex); >> goto wash; >> } > > This is *really* weird. Why would we need the list lock to do a > device_register()?
The device_register() is going to add the regulator to the regulator class list and this means that after this, someone could look up that regulator via ...
static struct regulator_dev *of_find_regulator_by_node(struct device_node *np) { struct device *dev; dev = class_find_device(®ulator_class, NULL, np, of_node_match); return dev ? dev_to_rdev(dev) : NULL; }
So I did not think that we would want someone to be able to look-up the regulator via of_find_regulator_by_node() until it had been registered successfully. In fact I believe that not locking around device_register() was causing some crashes when I was testing.
Cheers Jon
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