On Thu, 21 Apr 2022 at 01:14, Linus Walleij <linus.walleij@xxxxxxxxxx> wrote: > > On Sun, Apr 10, 2022 at 5:46 PM Jonathan Cameron <jic23@xxxxxxxxxx> wrote: > > On Sat, 9 Apr 2022 11:48:48 +0800 > > Zheyu Ma <zheyuma97@xxxxxxxxx> wrote: > > > > > When the driver fail at devm_regmap_init_i2c(), we will get the > > > following splat: > > > > > > [ 106.797388] WARNING: CPU: 4 PID: 413 at drivers/regulator/core.c:2257 _regulator_put+0x3ec/0x4e0 > > > [ 106.802183] RIP: 0010:_regulator_put+0x3ec/0x4e0 > > > [ 106.811237] Call Trace: > > > [ 106.811515] <TASK> > > > [ 106.811695] regulator_bulk_free+0x82/0xe0 > > > [ 106.812032] devres_release_group+0x319/0x3d0 > > > [ 106.812425] i2c_device_probe+0x766/0x940 > > > > > > Fix this by disabling the regulators at the error path. > > > > > > Signed-off-by: Zheyu Ma <zheyuma97@xxxxxxxxx> > > + CC Linus W as it's his driver. > > > > Fix looks correct to me, though the handling of runtime pm in here is > > probably more complex than it needs to be (and hence this odd error > > handling for this one place in the probe). > > At the time I discussed how to do runtime pm with Ulf Hansson a lot > and I think it was the state of the art at that time. It might have > changed since. It still looks good to me. One could switch the order of the calls to pm_runtime_disable() and pm_runtime_put_noidle(), but it's not a big thing. Whether it looks complicated or not, that's a different story. :-) Note that some drivers are always being built with CONFIG_PM being set, which allows some simplifications. Although, I don't think that's the case here, right? > > > > --- > > > drivers/iio/magnetometer/ak8974.c | 1 + > > > 1 file changed, 1 insertion(+) > > > > > > diff --git a/drivers/iio/magnetometer/ak8974.c b/drivers/iio/magnetometer/ak8974.c > > > index e54feacfb980..84bbf7ccc887 100644 > > > --- a/drivers/iio/magnetometer/ak8974.c > > > +++ b/drivers/iio/magnetometer/ak8974.c > > > @@ -862,6 +862,7 @@ static int ak8974_probe(struct i2c_client *i2c, > > > dev_err(&i2c->dev, "failed to allocate register map\n"); > > > pm_runtime_put_noidle(&i2c->dev); > > > pm_runtime_disable(&i2c->dev); > > > + regulator_bulk_disable(ARRAY_SIZE(ak8974->regs), ak8974->regs); > > Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > > Yours, > Linus Walleij Kind regards Uffe
