Message ID | 1484046069-7893-1-git-send-email-jonathanh@nvidia.com |
---|---|
State | Rejected |
Headers | show |
On Tue, Jan 10, 2017 at 11:01:09AM +0000, Jon Hunter wrote: > +++ b/drivers/regulator/core.c > @@ -1553,6 +1553,11 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) > } > } > > + if (r->dev.parent && !device_is_bound(r->dev.parent)) { > + put_device(&r->dev); > + return -EPROBE_DEFER; > + } > + I realised earlier that this will trigger when the supply and the consumer are part of the same PMIC which will cause issues as that's a fairly common setup and won't be resolved by deferring. Can you please modify this to only defer if the parent is not the same as the parent of the regulator we're currently resolving? Sorry, should've thought of this yesterday.
On 10/01/17 16:57, Mark Brown wrote: > * PGP Signed by an unknown key > > On Tue, Jan 10, 2017 at 11:01:09AM +0000, Jon Hunter wrote: > >> +++ b/drivers/regulator/core.c >> @@ -1553,6 +1553,11 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) >> } >> } >> >> + if (r->dev.parent && !device_is_bound(r->dev.parent)) { >> + put_device(&r->dev); >> + return -EPROBE_DEFER; >> + } >> + > > I realised earlier that this will trigger when the supply and the > consumer are part of the same PMIC which will cause issues as that's a > fairly common setup and won't be resolved by deferring. Can you please > modify this to only defer if the parent is not the same as the parent of > the regulator we're currently resolving? Sorry, should've thought of > this yesterday. OK, no problem. Will send out an update shortly. Cheers Jon
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 04baac9a165b..8adadcdfed1c 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1553,6 +1553,11 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) } } + if (r->dev.parent && !device_is_bound(r->dev.parent)) { + put_device(&r->dev); + return -EPROBE_DEFER; + } + /* Recursively resolve the supply of the supply */ ret = regulator_resolve_supply(r); if (ret < 0) {
When regulators are successfully registered, we check to see if the regulator is a supply for any other registered regulator and if so add the new regulator as the supply for the existing regulator(s). Some devices, such as Power Management ICs, may register a series of regulators when probed and there are cases where one of the regulators may fail to register and defer the probing of the parent device. In this case any successfully registered regulators would be unregistered so that they can be re-registered at some time later when the probe is attempted again. However, if one of the regulators that was registered was added as a supply to another registered regulator (that did not belong to the same parent device), then this supply regulator was unregister again because the parent device is probe deferred, then a regulator could be holding an invalid reference to a supply regulator that has been unregistered. This will lead to a system crash if that regulator is then used. Although it would be possible to check when unregistering a regulator if any other regulator in the system is using it as a supply, it still may not be possible to remove it as a supply if this other regulator is in use. Therefore, fix this by preventing any regulator from adding another regulator as a supply if the parent device for the supply regulator has not been bound. This will allow a parent device that is registering regulators to be probe deferred and ensure that none of the regulators it has registered are used as supplies for any other regulator. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> --- drivers/regulator/core.c | 5 +++++ 1 file changed, 5 insertions(+)