[PATCH 1/2] video: backlight: make backlight_class constant
From: Ricardo B. Marliere <hidden>
Date: 2024-03-05 12:21:26
Also in:
dri-devel, lkml
Subsystem:
backlight class/subsystem, framebuffer layer, the rest · Maintainers:
Lee Jones, Daniel Thompson, Jingoo Han, Helge Deller, Linus Torvalds
Since commit 43a7206b0963 ("driver core: class: make class_register() take
a const *"), the driver core allows for struct class to be in read-only
memory, so move the backlight_class structure to be declared at build time
placing it into read-only memory, instead of having to be dynamically
allocated at boot time.
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ricardo B. Marliere <redacted>
---
drivers/video/backlight/backlight.c | 29 ++++++++++++++++-------------
1 file changed, 16 insertions(+), 13 deletions(-)
diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 86e1cdc8e369..d2feaebfd84a 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c@@ -317,8 +317,6 @@ static ssize_t scale_show(struct device *dev, } static DEVICE_ATTR_RO(scale); -static struct class *backlight_class; - #ifdef CONFIG_PM_SLEEP static int backlight_suspend(struct device *dev) {
@@ -369,6 +367,12 @@ static struct attribute *bl_device_attrs[] = { }; ATTRIBUTE_GROUPS(bl_device); +static const struct class backlight_class = { + .name = "backlight", + .dev_groups = bl_device_groups, + .pm = &backlight_class_dev_pm_ops, +}; + /** * backlight_force_update - tell the backlight subsystem that hardware state * has changed
@@ -418,7 +422,7 @@ struct backlight_device *backlight_device_register(const char *name, mutex_init(&new_bd->update_lock); mutex_init(&new_bd->ops_lock); - new_bd->dev.class = backlight_class; + new_bd->dev.class = &backlight_class; new_bd->dev.parent = parent; new_bd->dev.release = bl_device_release; dev_set_name(&new_bd->dev, "%s", name);
@@ -510,7 +514,7 @@ struct backlight_device *backlight_device_get_by_name(const char *name) { struct device *dev; - dev = class_find_device_by_name(backlight_class, name); + dev = class_find_device_by_name(&backlight_class, name); return dev ? to_backlight_device(dev) : NULL; }
@@ -678,7 +682,7 @@ struct backlight_device *of_find_backlight_by_node(struct device_node *node) { struct device *dev; - dev = class_find_device(backlight_class, NULL, node, of_parent_match); + dev = class_find_device(&backlight_class, NULL, node, of_parent_match); return dev ? to_backlight_device(dev) : NULL; }
@@ -746,20 +750,19 @@ EXPORT_SYMBOL(devm_of_find_backlight); static void __exit backlight_class_exit(void) { - class_destroy(backlight_class); + class_unregister(&backlight_class); } static int __init backlight_class_init(void) { - backlight_class = class_create("backlight"); - if (IS_ERR(backlight_class)) { - pr_warn("Unable to create backlight class; errno = %ld\n", - PTR_ERR(backlight_class)); - return PTR_ERR(backlight_class); + int ret; + + ret = class_register(&backlight_class); + if (ret) { + pr_warn("Unable to create backlight class; errno = %d\n", ret); + return ret; } - backlight_class->dev_groups = bl_device_groups; - backlight_class->pm = &backlight_class_dev_pm_ops; INIT_LIST_HEAD(&backlight_dev_list); mutex_init(&backlight_dev_list_mutex); BLOCKING_INIT_NOTIFIER_HEAD(&backlight_notifier);
--
2.43.0