From 6accc376a7482ecec2537e3e092b4f06e11d5994 Mon Sep 17 00:00:00 2001 From: Kent Gibson Date: Wed, 8 Jul 2020 12:15:51 +0800 Subject: [PATCH] gpiolib: cdev: use blocking notifier call chain instead of atomic 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 Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-cdev.c | 24 ++++++++++++------------ drivers/gpio/gpiolib.c | 14 +++++++------- drivers/gpio/gpiolib.h | 2 +- 3 files changed, 20 insertions(+), 20 deletions(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index d50339ef6f05..352d815bbd07 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -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); diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4d267c69482c..80137c1b3cdc 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -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; } diff --git a/drivers/gpio/gpiolib.h b/drivers/gpio/gpiolib.h index 2dee4e1e12dc..6709f79c02dd 100644 --- a/drivers/gpio/gpiolib.h +++ b/drivers/gpio/gpiolib.h @@ -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 /*