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authorViresh Kumar <viresh.kumar@linaro.org>2016-10-27 13:20:18 +0300
committerLee Jones <lee.jones@linaro.org>2016-11-29 11:21:27 +0300
commit202b56890aead063f90b6995554d4602dbd7752e (patch)
tree84a0ffb4694f3d3a11706d3afdfccb88e72c82ca /drivers/mfd
parent8ca9edc837932469b81b8b47ea43a074b6add970 (diff)
downloadlinux-202b56890aead063f90b6995554d4602dbd7752e.tar.xz
mfd: wm8994-core: Don't use managed regulator bulk get API
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>
Diffstat (limited to 'drivers/mfd')
-rw-r--r--drivers/mfd/wm8994-core.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/mfd/wm8994-core.c b/drivers/mfd/wm8994-core.c
index 95e6bc55adbb..953d0790ffd5 100644
--- a/drivers/mfd/wm8994-core.c
+++ b/drivers/mfd/wm8994-core.c
@@ -393,8 +393,13 @@ static int wm8994_device_init(struct wm8994 *wm8994, int irq)
BUG();
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);
}