mfd: wm8994-core: Don't use managed regulator bulk get API (202b5689) · Commits · 戴 / test

The kernel WARNs and then crashes today if wm8994_device_init() fails after calling devm_regulator_bulk_get(). That happens because there are multiple devices involved here and the order in which managed resources are freed isn't correct. The regulators are added as children of wm8994->dev. Whereas, devm_regulator_bulk_get() receives wm8994->dev as the device, though it gets the same regulators which were added as children of wm8994->dev earlier. During failures, the children are removed first and the core eventually calls regulator_unregister() for them. As regulator_put() was never done for them (opposite of devm_regulator_bulk_get()), the kernel WARNs at WARN_ON(rdev->open_count); And eventually it crashes from debugfs_remove_recursive(). Fix the kernel warnings and crashes by using regulator_bulk_get() instead of devm_regulator_bulk_get() and explicitly freeing the supplies in exit paths. Tested on Exynos 5250, dual core ARM A15 machine. Signed-off-by:

Viresh Kumar <viresh.kumar@linaro.org> Acked-by:

Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by:

Lee Jones <lee.jones@linaro.org>

drivers/mfd/wm8994-core.c

+11 −3

Original line number	Diff line number	Diff line
		@@ -394,7 +394,12 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
		goto err;
		}

		ret = devm_regulator_bulk_get(wm8994->dev, wm8994->num_supplies,
		/*
		* Can't use devres helper here as some of the supplies are provided by
		* wm8994->dev's children (regulators) and those regulators are
		* unregistered by the devres core before the supplies are freed.
		*/
		ret = regulator_bulk_get(wm8994->dev, wm8994->num_supplies,
		wm8994->supplies);
		if (ret != 0) {
		dev_err(wm8994->dev, "Failed to get supplies: %d\n", ret);
		@@ -404,7 +409,7 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
		ret = regulator_bulk_enable(wm8994->num_supplies, wm8994->supplies);
		if (ret != 0) {
		dev_err(wm8994->dev, "Failed to enable supplies: %d\n", ret);
		goto err;
		goto err_regulator_free;
		}

		ret = wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET);
		@@ -595,6 +600,8 @@ err_irq:
		err_enable:
		regulator_bulk_disable(wm8994->num_supplies,
		wm8994->supplies);
		err_regulator_free:
		regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
		err:
		mfd_remove_devices(wm8994->dev);
		return ret;
		@@ -605,6 +612,7 @@ static void wm8994_device_exit(struct wm8994 *wm8994)
		pm_runtime_disable(wm8994->dev);
		wm8994_irq_exit(wm8994);
		regulator_bulk_disable(wm8994->num_supplies, wm8994->supplies);
		regulator_bulk_free(wm8994->num_supplies, wm8994->supplies);
		mfd_remove_devices(wm8994->dev);
		}

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