[PATCH 10/13] leds: wm831x-status: fix attribute-creation race

From: Johan Hovold
Date: Wed Jun 25 2014 - 13:11:27 EST


Use the attribute groups of the led-class to create the src attribute
during probe in order to avoid racing with userspace.

Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/leds/leds-wm831x-status.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)

diff --git a/drivers/leds/leds-wm831x-status.c b/drivers/leds/leds-wm831x-status.c
index e72c974142d0..1b71e0701002 100644
--- a/drivers/leds/leds-wm831x-status.c
+++ b/drivers/leds/leds-wm831x-status.c
@@ -219,6 +219,12 @@ static ssize_t wm831x_status_src_store(struct device *dev,

static DEVICE_ATTR(src, 0644, wm831x_status_src_show, wm831x_status_src_store);

+static struct attribute *wm831x_status_attrs[] = {
+ &dev_attr_src.attr,
+ NULL
+};
+ATTRIBUTE_GROUPS(wm831x_status);
+
static int wm831x_status_probe(struct platform_device *pdev)
{
struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
@@ -232,8 +238,7 @@ static int wm831x_status_probe(struct platform_device *pdev)
res = platform_get_resource(pdev, IORESOURCE_REG, 0);
if (res == NULL) {
dev_err(&pdev->dev, "No register resource\n");
- ret = -EINVAL;
- goto err;
+ return -EINVAL;
}

drvdata = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_status),
@@ -284,31 +289,21 @@ static int wm831x_status_probe(struct platform_device *pdev)
drvdata->cdev.default_trigger = pdata.default_trigger;
drvdata->cdev.brightness_set = wm831x_status_set;
drvdata->cdev.blink_set = wm831x_status_blink_set;
+ drvdata->cdev.groups = wm831x_status_groups;

ret = led_classdev_register(wm831x->dev, &drvdata->cdev);
if (ret < 0) {
dev_err(&pdev->dev, "Failed to register LED: %d\n", ret);
- goto err_led;
+ return ret;
}

- ret = device_create_file(drvdata->cdev.dev, &dev_attr_src);
- if (ret != 0)
- dev_err(&pdev->dev,
- "No source control for LED: %d\n", ret);
-
return 0;
-
-err_led:
- led_classdev_unregister(&drvdata->cdev);
-err:
- return ret;
}

static int wm831x_status_remove(struct platform_device *pdev)
{
struct wm831x_status *drvdata = platform_get_drvdata(pdev);

- device_remove_file(drvdata->cdev.dev, &dev_attr_src);
led_classdev_unregister(&drvdata->cdev);

return 0;
--
1.8.5.5

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