regulator: check that dummy regulator has been probed before using it

Due to asynchronous driver probing there is a chance that the dummy
regulator hasn't already been probed when first accessing it.

Cc: stable@vger.kernel.org
Signed-off-by: Christian Eggers <ceggers@arri.de>
Link: https://patch.msgid.link/20250313103051.32430-3-ceggers@arri.de
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index c993ab48f4153965706567b3f497d461c46f535b..00a7f3617cd8ec6c8393b964e9f4ccbcff0333bd 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2074,6 +2074,10 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
 
                if (have_full_constraints()) {
                        r = dummy_regulator_rdev;
+                       if (!r) {
+                               ret = -EPROBE_DEFER;
+                               goto out;
+                       }
                        get_device(&r->dev);
                } else {
                        dev_err(dev, "Failed to resolve %s-supply for %s\n",
@@ -2091,6 +2095,10 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
                        goto out;
                }
                r = dummy_regulator_rdev;
+               if (!r) {
+                       ret = -EPROBE_DEFER;
+                       goto out;
+               }
                get_device(&r->dev);
        }
 
@@ -2219,8 +2227,10 @@ struct regulator *_regulator_get_common(struct regulator_dev *rdev, struct devic
                         * enabled, even if it isn't hooked up, and just
                         * provide a dummy.
                         */
-                       dev_warn(dev, "supply %s not found, using dummy regulator\n", id);
                        rdev = dummy_regulator_rdev;
+                       if (!rdev)
+                               return ERR_PTR(-EPROBE_DEFER);
+                       dev_warn(dev, "supply %s not found, using dummy regulator\n", id);
                        get_device(&rdev->dev);
                        break;