Messages in this thread Patch in this message | | | Date | Wed, 30 Aug 2023 19:35:33 +0200 | Subject | [PATCH v2 6/7] regulator/core: regulator_lock_two: propagate error up | From | Michał Mirosław <> |
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Fix up error paths from regulator_lock_two(): although it should not fail, returning with half-locked state after issuing a WARN() asks for even more trouble.
Fixes: cba6cfdc7c3f ("regulator: core: Avoid lockdep reports when resolving supplies") Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> --- v2: - updated kerneldoc - call ww_acquire_done() on all exits --- drivers/regulator/core.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 7201927c5d5b..3f9621621da9 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -209,11 +209,12 @@ static void regulator_unlock(struct regulator_dev *rdev) * @rdev2: second regulator * @ww_ctx: w/w mutex acquire context * - * Locks both rdevs using the regulator_ww_class. + * Locks both rdevs using the regulator_ww_class. Returns error if an + * unexpected error has been detected during a locking sequence. */ -static void regulator_lock_two(struct regulator_dev *rdev1, - struct regulator_dev *rdev2, - struct ww_acquire_ctx *ww_ctx) +static int regulator_lock_two(struct regulator_dev *rdev1, + struct regulator_dev *rdev2, + struct ww_acquire_ctx *ww_ctx) { struct regulator_dev *held, *contended; int ret; @@ -222,10 +223,13 @@ static void regulator_lock_two(struct regulator_dev *rdev1, /* Try to just grab both of them */ ret = regulator_lock_nested(rdev1, ww_ctx); - WARN_ON(ret); + if (WARN_ON(ret)) + goto exit; ret = regulator_lock_nested(rdev2, ww_ctx); - if (ret != -EDEADLOCK) { - WARN_ON(ret); + if (!ret) + goto exit; + if (WARN_ON(ret != -EDEADLOCK)) { + regulator_unlock(rdev1); goto exit; } @@ -239,13 +243,15 @@ static void regulator_lock_two(struct regulator_dev *rdev1, ret = regulator_lock_nested(contended, ww_ctx); if (ret != -EDEADLOCK) { - WARN_ON(ret); + if (WARN_ON(ret)) + regulator_unlock(held); break; } } exit: ww_acquire_done(ww_ctx); + return ret; } /** @@ -2113,7 +2119,11 @@ static int regulator_resolve_supply(struct regulator_dev *rdev) * between rdev->supply null check and setting rdev->supply in * set_supply() from concurrent tasks. */ - regulator_lock_two(rdev, r, &ww_ctx); + ret = regulator_lock_two(rdev, r, &ww_ctx); + if (ret < 0) { + put_device(&r->dev); + return ret; + } /* Supply just resolved by a concurrent task? */ if (rdev->supply) { -- 2.39.2
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