From patchwork Thu Mar 28 11:59:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 784190 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id F2A2A5474B; Thu, 28 Mar 2024 11:59:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711627158; cv=none; b=ZCHpC5+hZ1Ed8fAxnPm/djL4jkCl/EZb6URMPC/Zqo4y/L9HvohVb0reUvs1EjKyhTHnd/7zAwJApQdv6l5p+1LSh5fXsFgTSQxvZu0i3q+Hxe784Zmugmn1IYIuz7YEQa4LnB6owfkS9rqDf/6+0Ffmy6hLYz8XmKuj4IZzYVU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711627158; c=relaxed/simple; bh=8tDAHUDVfUVkniIhz2Tjlxyx9+yhjE02ZhpIawN3e88=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=gQe0mp66i1tDN4nvDnZs1Tai65z8wcSTcvh3kY3XEEYZLhtRK6UM96CXShfwTvlNFc0qVw9xjvg9/PF9PJSxIqCUZXguoFfR+TZxCDWOeg62bueBmzdlNLKEryyo1BJS+HevmxKJRzd3bpnCZnJydpr5GDq+mlpcec+s/eDZqw4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=mFU4EWgf; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="mFU4EWgf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCF4FC43390; Thu, 28 Mar 2024 11:59:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1711627157; bh=8tDAHUDVfUVkniIhz2Tjlxyx9+yhjE02ZhpIawN3e88=; h=From:To:Cc:Subject:Date:From; b=mFU4EWgfLkursYUxABDp9NsVLp90HdFN3faN6m/bgMh+UFLqHeoWncr753xBJjsJ4 X4d8z9pPBJng4tSxlbFZMtPQ4c+WILU9TySRjYPDSLvyu8e9bpbT4YQJedwQ3s2XEc PsO8smAb94iIYyflRDvCcmlo0iKyA8Vjpr3OX45g= From: Greg Kroah-Hartman To: lee@kernel.org Cc: dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org, daniel.thompson@linaro.org, jingoohan1@gmail.com, deller@gmx.de, "Ricardo B. Marliere" , Greg Kroah-Hartman Subject: [PATCH v2 1/2] video: backlight: make backlight_class constant Date: Thu, 28 Mar 2024 12:59:06 +0100 Message-ID: <2024032805-putdown-mushy-a0f9@gregkh> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-fbdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3406; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=/aKgYyLp0Ixe4eLFmIE3xueHTfYuhhXATaHPaS0rmDA=; b=owGbwMvMwCRo6H6F97bub03G02pJDGms0Z17LUtTKjdU+utYFJ/gXeDZFML8gy2gcbVQF4P6f pacubUdsSwMgkwMsmKKLF+28RzdX3FI0cvQ9jTMHFYmkCEMXJwCMBHrRwzzvRJX//9SM8Uj8ERD xJWextUsf03dGBacODbL4ZtbYOoHf5cm9XNW5TftP28FAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 From: "Ricardo B. Marliere" 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 Suggested-by: Greg Kroah-Hartman Signed-off-by: "Ricardo B. Marliere" Signed-off-by: Greg Kroah-Hartman --- v2: rebased on 6.9-rc1 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);