ASoC: cx20442: Don't ignore regulator_get() errors.

In its current shape, the driver just ignores errors returned by
regulator_get() at component_probe().  This doesn't hurt on Amstrad
Delta board as long as it registers the codec device at late_initcall,
when the regulator which depends on basic-mmio-gpio device (probed as
late as at dev_initcall) is already available.  Otherwise the driver
may end up trying to control a codec which is not powered up.

Remove that dependency on initialization order by handling the error.
If the regulator is not yet available and -ENODEV is returned, convert
it to -EPROBE_DEFER to get another chance.

Signed-off-by: Janusz Krzysztofik <jmkrzyszt@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Janusz Krzysztofik 2018-06-24 20:14:41 +02:00 committed by Mark Brown
parent f4c277b817
commit 50c678772a
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@ -362,8 +362,27 @@ static int cx20442_component_probe(struct snd_soc_component *component)
return -ENOMEM;
cx20442->por = regulator_get(component->dev, "POR");
if (IS_ERR(cx20442->por))
dev_warn(component->dev, "failed to get the regulator");
if (IS_ERR(cx20442->por)) {
int err = PTR_ERR(cx20442->por);
dev_warn(component->dev, "failed to get POR supply (%d)", err);
/*
* When running on a non-dt platform and requested regulator
* is not available, regulator_get() never returns
* -EPROBE_DEFER as it is not able to justify if the regulator
* may still appear later. On the other hand, the board can
* still set full constraints flag at late_initcall in order
* to instruct regulator_get() to return a dummy one if
* sufficient. Hence, if we get -ENODEV here, let's convert
* it to -EPROBE_DEFER and wait for the board to decide or
* let Deferred Probe infrastructure handle this error.
*/
if (err == -ENODEV)
err = -EPROBE_DEFER;
kfree(cx20442);
return err;
}
cx20442->tty = NULL;
snd_soc_component_set_drvdata(component, cx20442);