On Tue, Jan 12, 2021 at 10:34:19PM +0100, Marek Szyprowski wrote:
> ======================================================
> WARNING: possible circular locking dependency detected
> 5.11.0-rc1-00008-geaa7995c529b #10095 Not tainted
> ------------------------------------------------------
> swapper/0/1 is trying to acquire lock:
> c12e1b80 (regulator_list_mutex){+.+.}-{3:3}, at:
> regulator_lock_dependent+0x4c/0x2b0
If you're sending backtraces or other enormous reports like this please
run them through addr2line first so that things are a bit more leigible.
> but task is already holding lock:
> df7190c0 (regulator_ww_class_mutex){+.+.}-{3:3}, at:
> regulator_resolve_supply+0x44/0x318
>
> which lock already depends on the new lock.
Does this help (completely untested):
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 3ae5ccd9277d..7d1422b00974 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1823,17 +1823,6 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
if (rdev->supply)
return 0;
- /*
- * Recheck rdev->supply with rdev->mutex lock held to avoid a race
- * between rdev->supply null check and setting rdev->supply in
- * set_supply() from concurrent tasks.
- */
- regulator_lock(rdev);
-
- /* Supply just resolved by a concurrent task? */
- if (rdev->supply)
- goto out;
-
r = regulator_dev_lookup(dev, rdev->supply_name);
if (IS_ERR(r)) {
ret = PTR_ERR(r);
@@ -1885,10 +1874,23 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
goto out;
}
+ /*
+ * Recheck rdev->supply with rdev->mutex lock held to avoid a race
+ * between rdev->supply null check and setting rdev->supply in
+ * set_supply() from concurrent tasks.
+ */
+ regulator_lock(rdev);
+
+ /* Supply just resolved by a concurrent task? */
+ if (rdev->supply) {
+ put_device(&r->dev);
+ goto out_rdev_lock;
+ }
+
ret = set_supply(rdev, r);
if (ret < 0) {
put_device(&r->dev);
- goto out;
+ goto out_rdev_lock;
}
/*
@@ -1901,12 +1903,13 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
if (ret < 0) {
_regulator_put(rdev->supply);
rdev->supply = NULL;
- goto out;
+ goto out_rdev_lock;
}
}
-out:
+out_rdev_lock:
regulator_unlock(rdev);
+out:
return ret;
}
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