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 <[email protected]> --- Created and tested on linux-4.18-rc1 sound/soc/codecs/cx20442.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/sound/soc/codecs/cx20442.c b/sound/soc/codecs/cx20442.c index 07dd33b09596..ab174b5114dc 100644 --- a/sound/soc/codecs/cx20442.c +++ b/sound/soc/codecs/cx20442.c @@ -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); -- 2.16.4
