redonkable/alistair23-linux
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gpiolib: cdev: use blocking notifier call chain instead of atomic

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Replace usage of atomic_notifier_call_chain with
blocking_notifier_call_chain as the notifier function,
lineinfo_changed_notify, calls gpio_desc_to_lineinfo,
which calls pinctrl_gpio_can_use_line, which can sleep.

The chain isn't being called from an atomic context so the
the blocking notifier is a suitable substitute.

Signed-off-by: Kent Gibson <warthog618@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
This commit is contained in:
Kent Gibson 2020-07-08 12:15:51 +08:00 committed by Bartosz Golaszewski
parent 0cdc85a371
commit 6accc376a7
3 changed files with 20 additions and 20 deletions
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24
drivers/gpio/gpiolib-cdev.c
View file

@ -158,8 +158,8 @@ static long linehandle_set_config(struct linehandle_state *lh,
return ret;
}
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_CONFIG, desc);
blocking_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_CONFIG, desc);
}
return 0;
}
@ -325,8 +325,8 @@ static int linehandle_create(struct gpio_device *gdev, void __user *ip)
goto out_free_descs;
}
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
blocking_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
dev_dbg(&gdev->dev, "registered chardev handle for line %d\n",
offset);
@ -674,8 +674,8 @@ static int lineevent_create(struct gpio_device *gdev, void __user *ip)
if (ret)
goto out_free_desc;
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
blocking_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
le->irq = gpiod_to_irq(desc);
if (le->irq <= 0) {
@ -1049,8 +1049,8 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
priv->gdev = gdev;
priv->lineinfo_changed_nb.notifier_call = lineinfo_changed_notify;
ret = atomic_notifier_chain_register(&gdev->notifier,
&priv->lineinfo_changed_nb);
ret = blocking_notifier_chain_register(&gdev->notifier,
&priv->lineinfo_changed_nb);
if (ret)
goto out_free_bitmap;
@ -1064,8 +1064,8 @@ static int gpio_chrdev_open(struct inode *inode, struct file *file)
return ret;
out_unregister_notifier:
atomic_notifier_chain_unregister(&gdev->notifier,
&priv->lineinfo_changed_nb);
blocking_notifier_chain_unregister(&gdev->notifier,
&priv->lineinfo_changed_nb);
out_free_bitmap:
bitmap_free(priv->watched_lines);
out_free_priv:
@ -1085,8 +1085,8 @@ static int gpio_chrdev_release(struct inode *inode, struct file *file)
struct gpio_device *gdev = priv->gdev;
bitmap_free(priv->watched_lines);
atomic_notifier_chain_unregister(&gdev->notifier,
&priv->lineinfo_changed_nb);
blocking_notifier_chain_unregister(&gdev->notifier,
&priv->lineinfo_changed_nb);
put_device(&gdev->dev);
kfree(priv);

14
drivers/gpio/gpiolib.c
View file

@ -615,7 +615,7 @@ int gpiochip_add_data_with_key(struct gpio_chip *gc, void *data,
spin_unlock_irqrestore(&gpio_lock, flags);
ATOMIC_INIT_NOTIFIER_HEAD(&gdev->notifier);
BLOCKING_INIT_NOTIFIER_HEAD(&gdev->notifier);
#ifdef CONFIG_PINCTRL
INIT_LIST_HEAD(&gdev->pin_ranges);
@ -2049,8 +2049,8 @@ static bool gpiod_free_commit(struct gpio_desc *desc)
}
spin_unlock_irqrestore(&gpio_lock, flags);
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_RELEASED, desc);
blocking_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_RELEASED, desc);
return ret;
}
@ -3927,8 +3927,8 @@ struct gpio_desc *__must_check gpiod_get_index(struct device *dev,
return ERR_PTR(ret);
}
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
blocking_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
return desc;
}
@ -3995,8 +3995,8 @@ struct gpio_desc *fwnode_get_named_gpiod(struct fwnode_handle *fwnode,
return ERR_PTR(ret);
}
atomic_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
blocking_notifier_call_chain(&desc->gdev->notifier,
GPIOLINE_CHANGED_REQUESTED, desc);
return desc;
}

2
drivers/gpio/gpiolib.h
View file

@ -56,7 +56,7 @@ struct gpio_device {
const char *label;
void *data;
struct list_head list;
struct atomic_notifier_head notifier;
struct blocking_notifier_head notifier;
#ifdef CONFIG_PINCTRL
/*