Messages in this thread | | | Date | Wed, 04 Mar 2015 14:45:00 +0100 | From | Javier Martinez Canillas <> | Subject | Re: [PATCH 1/1] regulator: Only enable disabled regulators on resume |
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Hello Doug,
On 03/03/2015 08:05 PM, Javier Martinez Canillas wrote: > On 03/03/2015 06:24 PM, Doug Anderson wrote: >>> >>> diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c >>> index f2452148c8da..8551400d57e4 100644 >>> --- a/drivers/regulator/core.c >>> +++ b/drivers/regulator/core.c >>> @@ -3816,9 +3816,11 @@ int regulator_suspend_finish(void) >>> list_for_each_entry(rdev, ®ulator_list, list) { >>> mutex_lock(&rdev->mutex); >>> if (rdev->use_count > 0 || rdev->constraints->always_on) { >>> - error = _regulator_do_enable(rdev); >>> - if (error) >>> - ret = error; >>> + if (!_regulator_is_enabled(rdev)) { >> >> Looking at _regulator_enable() I see that _regulator_is_enabled() >> could return an error. Should we be checking? Maybe we should have a >> helper function called by both callers? >> > > Thanks for pointing that out. I'll change it on v2 as well. >
Looking at the code now I remember why I didn't checked for an error in _regulator_is_enable(), sorry I wrote the patch months ago.
The thing is that _regulator_is_enabled() used to return -EINVAL if the rdev didn't have an .is_enabled callback but that changed in commit 9a7f6a4c6edc8 ("regulator: Assume regulators are enabled if they don't report anything") and now returns 1 in that case. But _regulator_enable() was not changed and is still checking for -EINVAL which seems to me like a left over after the mentioned commit.
Also, _regulator_enable() is the only place that has a check for a negative errno value returned by _regulator_is_enabled().
All other functions calling _regulator_is_enabled() seems to assume that a return value != 0 means that the regulator is enabled.
Is true though that the rdev .is_enabled callback function may return an error so I don't know if all those callers are missing a check or if it's a design decision to assume that a regulator should be enabled if the actual hardware state can't be obtained.
Best regards, Javier
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