From: Andrew Halaney ahalaney@redhat.com
[ Upstream commit c32f1ebfd26bece77141257864ed7b4720da1557 ]
If regulator_enable() fails, enable_count is incremented still. A consumer, assuming no matching regulator_disable() is necessary on failure, will then get this error message upon regulator_put() since enable_count is non-zero:
[ 1.277418] WARNING: CPU: 3 PID: 1 at drivers/regulator/core.c:2304 _regulator_put.part.0+0x168/0x170
The consumer could try to fix this in their driver by cleaning up on error from regulator_enable() (i.e. call regulator_disable()), but that results in the following since regulator_enable() failed and didn't increment user_count:
[ 1.258112] unbalanced disables for vreg_l17c [ 1.262606] WARNING: CPU: 4 PID: 1 at drivers/regulator/core.c:2899 _regulator_disable+0xd4/0x190
Fix this by decrementing enable_count upon failure to enable.
With this in place, just the reason for failure to enable is printed as expected and developers can focus on the root cause of their issue instead of thinking their usage of the regulator consumer api is incorrect. For example, in my case:
[ 1.240426] vreg_l17c: invalid input voltage found
Fixes: 5451781dadf8 ("regulator: core: Only count load for enabled consumers") Signed-off-by: Andrew Halaney ahalaney@redhat.com Reviewed-by: Douglas Anderson dianders@chromium.org Reviewed-by: Brian Masney bmasney@redhat.com Link: https://lore.kernel.org/r/20220819194336.382740-1-ahalaney@redhat.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/regulator/core.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index f4f28e5888b1c..43613db7af754 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -2688,13 +2688,18 @@ static int _regulator_do_enable(struct regulator_dev *rdev) */ static int _regulator_handle_consumer_enable(struct regulator *regulator) { + int ret; struct regulator_dev *rdev = regulator->rdev;
lockdep_assert_held_once(&rdev->mutex.base);
regulator->enable_count++; - if (regulator->uA_load && regulator->enable_count == 1) - return drms_uA_update(rdev); + if (regulator->uA_load && regulator->enable_count == 1) { + ret = drms_uA_update(rdev); + if (ret) + regulator->enable_count--; + return ret; + }
return 0; }