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path: root/drivers/gpio/gpiolib.c
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Diffstat (limited to 'drivers/gpio/gpiolib.c')
-rw-r--r--drivers/gpio/gpiolib.c34
1 files changed, 29 insertions, 5 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 40f2d7f69be2..182136d98b97 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1158,8 +1158,19 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
struct gpioline_info *info)
{
struct gpio_chip *gc = desc->gdev->chip;
+ bool ok_for_pinctrl;
unsigned long flags;
+ /*
+ * This function takes a mutex so we must check this before taking
+ * the spinlock.
+ *
+ * FIXME: find a non-racy way to retrieve this information. Maybe a
+ * lock common to both frameworks?
+ */
+ ok_for_pinctrl =
+ pinctrl_gpio_can_use_line(gc->base + info->line_offset);
+
spin_lock_irqsave(&gpio_lock, flags);
if (desc->name) {
@@ -1186,7 +1197,7 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
test_bit(FLAG_USED_AS_IRQ, &desc->flags) ||
test_bit(FLAG_EXPORT, &desc->flags) ||
test_bit(FLAG_SYSFS, &desc->flags) ||
- !pinctrl_gpio_can_use_line(gc->base + info->line_offset))
+ !ok_for_pinctrl)
info->flags |= GPIOLINE_FLAG_KERNEL;
if (test_bit(FLAG_IS_OUT, &desc->flags))
info->flags |= GPIOLINE_FLAG_IS_OUT;
@@ -1227,6 +1238,7 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
void __user *ip = (void __user *)arg;
struct gpio_desc *desc;
__u32 offset;
+ int hwgpio;
/* We fail any subsequent ioctl():s when the chip is gone */
if (!gc)
@@ -1259,13 +1271,19 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (IS_ERR(desc))
return PTR_ERR(desc);
+ hwgpio = gpio_chip_hwgpio(desc);
+
+ if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL &&
+ test_bit(hwgpio, priv->watched_lines))
+ return -EBUSY;
+
gpio_desc_to_lineinfo(desc, &lineinfo);
if (copy_to_user(ip, &lineinfo, sizeof(lineinfo)))
return -EFAULT;
if (cmd == GPIO_GET_LINEINFO_WATCH_IOCTL)
- set_bit(gpio_chip_hwgpio(desc), priv->watched_lines);
+ set_bit(hwgpio, priv->watched_lines);
return 0;
} else if (cmd == GPIO_GET_LINEHANDLE_IOCTL) {
@@ -1280,7 +1298,12 @@ static long gpio_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
if (IS_ERR(desc))
return PTR_ERR(desc);
- clear_bit(gpio_chip_hwgpio(desc), priv->watched_lines);
+ hwgpio = gpio_chip_hwgpio(desc);
+
+ if (!test_bit(hwgpio, priv->watched_lines))
+ return -EBUSY;
+
+ clear_bit(hwgpio, priv->watched_lines);
return 0;
}
return -EINVAL;
@@ -5289,8 +5312,9 @@ static int __init gpiolib_dev_init(void)
gpiolib_initialized = true;
gpiochip_setup_devs();
- if (IS_ENABLED(CONFIG_OF_DYNAMIC))
- WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
+#if IS_ENABLED(CONFIG_OF_DYNAMIC) && IS_ENABLED(CONFIG_OF_GPIO)
+ WARN_ON(of_reconfig_notifier_register(&gpio_of_notifier));
+#endif /* CONFIG_OF_DYNAMIC && CONFIG_OF_GPIO */
return ret;
}