| Message ID | 4083086.03MkICpY7S@wuerfel |
|---|---|
| State | New |
| Headers | show |
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 4cf1390784e5..c9bdca5f3b9b 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -138,18 +138,10 @@ static bool have_full_constraints(void) */ static void regulator_lock_supply(struct regulator_dev *rdev) { - struct regulator *supply; - int i = 0; - - while (1) { - mutex_lock_nested(&rdev->mutex, i++); - supply = rdev->supply; - - if (!rdev->supply) - return; + int i; - rdev = supply->rdev; - } + for (i = 0; rdev->supply; rdev = rdev->supply->rdev, i++) + mutex_lock_nested(&rdev->mutex, i); } /**
The second argument of the mutex_lock_nested() helper is only evaluated if CONFIG_DEBUG_LOCK_ALLOC is set. Otherwise we get this build warning for the new regulator_lock_supply function: drivers/regulator/core.c: In function 'regulator_lock_supply': drivers/regulator/core.c:142:6: warning: unused variable 'i' [-Wunused-variable] To avoid the warning, this restructures the code to make it both simpler and to move the 'i++' outside of the mutex_lock_nested call, where it is now always used and the variable is not flagged as unused. We had some discussion about changing mutex_lock_nested to an inline function, which would make the code do the right thing here, but in the end decided against it, in order to guarantee that mutex_lock_nested() does not introduced overhead without CONFIG_DEBUG_LOCK_ALLOC. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 9f01cd4a915 ("regulator: core: introduce function to lock regulators and its supplies") Link: http://permalink.gmane.org/gmane.linux.kernel/2068900 --- This is a different approach I came up with now, feel free to pick either v3a or v3b of the patch, whichever seems more appropriate to you. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/