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authorDouglas Anderson <dianders@chromium.org>2018-11-20 09:52:54 -0800
committerMark Brown <broonie@kernel.org>2018-11-22 14:38:12 +0000
commit1fc12b05895ea50386f0e666f84053f0c8307943 (patch)
treeabb9f2f4614fa594d9134c3c9d1945a04bf12fc4 /drivers/regulator
parent5451781dadf85000665e0e2c3288e9e0f34b860a (diff)
regulator: core: Avoid propagating to supplies when possible
When we called regulator_enable() on a regulator we'd end up propagating that call all the way up the chain every time. This is a bit of a waste of time. A child regulator already refcounts its own enables so it should avoid passing on to its parent unless the refcount transitioned between 0 and 1. Historically this hasn't been a huge problem since we skipped dealing with enable for always-on regulators. In a previous patch, however, we removed the always-on optimization. On one system, the debugfs regulator_summary was now showing a "use_count" of 33 for a top-level regulator. Let's implement this optimization. This turns out to be fairly trivial with the recent reorganization of the regulator core. NOTE: as part of this patch I'll make "always-on" regulators start with a use count of 1. This keeps the counts clean when recursively resolving regulators. ALSO NOTE: this commit also contains somewhat of a bug fix to regulator_force_disable(). It was incorrectly looping over "rdev->open_count" when it should have been looping over use_count. We have to touch that code anyway (since we should no longer loop at all), so we'll fix it together in one patch. Also: since this comes after commit f8702f9e4aa7 ("regulator: core: Use ww_mutex for regulators locking") we can now move to use _regulator_disable() for our supply and keep it in the lock. Signed-off-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/regulator')
-rw-r--r--drivers/regulator/core.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 26a0c523ed86..03a03763457c 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -1822,6 +1822,7 @@ static int regulator_resolve_supply(struct regulator_dev *rdev)
rdev->supply = NULL;
return ret;
}
+ rdev->use_count = 1;
}
return 0;
@@ -2491,7 +2492,7 @@ static int _regulator_enable(struct regulator *regulator)
lockdep_assert_held_once(&rdev->mutex.base);
- if (rdev->supply) {
+ if (rdev->use_count == 0 && rdev->supply) {
ret = _regulator_enable(rdev->supply);
if (ret < 0)
return ret;
@@ -2539,7 +2540,7 @@ err_consumer_disable:
_regulator_handle_consumer_disable(regulator);
err_disable_supply:
- if (rdev->supply)
+ if (rdev->use_count == 0 && rdev->supply)
_regulator_disable(rdev->supply);
return ret;
@@ -2648,7 +2649,7 @@ static int _regulator_disable(struct regulator *regulator)
if (ret == 0 && rdev->coupling_desc.n_coupled > 1)
ret = regulator_balance_voltage(rdev, PM_SUSPEND_ON);
- if (ret == 0 && rdev->supply)
+ if (ret == 0 && rdev->use_count == 0 && rdev->supply)
ret = _regulator_disable(rdev->supply);
return ret;
@@ -2733,11 +2734,10 @@ int regulator_force_disable(struct regulator *regulator)
ret = drms_uA_update(rdev);
}
- regulator_unlock_dependent(rdev, &ww_ctx);
+ if (rdev->use_count != 0 && rdev->supply)
+ _regulator_disable(rdev->supply);
- if (rdev->supply)
- while (rdev->open_count--)
- regulator_disable(rdev->supply);
+ regulator_unlock_dependent(rdev, &ww_ctx);
return ret;
}