regulator: Fix lockdep warning resolving supplies
authorMark Brown <broonie@kernel.org>
Fri, 22 Jan 2021 13:20:42 +0000 (13:20 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 13 Feb 2021 12:55:14 +0000 (13:55 +0100)
commitbf9e4307920ffc4fc03ede270f93f2b26275df5b
tree094bf29fd094e82da63a77d58064018fb7fc8032
parentfb8f9b2f7d229a8bc74db1cfa53814a0d6b42b7f
regulator: Fix lockdep warning resolving supplies

[ Upstream commit 14a71d509ac809dcf56d7e3ca376b15d17bd0ddd ]

With commit eaa7995c529b54 (regulator: core: avoid
regulator_resolve_supply() race condition) we started holding the rdev
lock while resolving supplies, an operation that requires holding the
regulator_list_mutex. This results in lockdep warnings since in other
places we take the list mutex then the mutex on an individual rdev.

Since the goal is to make sure that we don't call set_supply() twice
rather than a concern about the cost of resolution pull the rdev lock
and check for duplicate resolution down to immediately before we do the
set_supply() and drop it again once the allocation is done.

Fixes: eaa7995c529b54 (regulator: core: avoid regulator_resolve_supply() race condition)
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210122132042.10306-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/regulator/core.c