Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751512AbWHKFJb (ORCPT ); Fri, 11 Aug 2006 01:09:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751510AbWHKFJK (ORCPT ); Fri, 11 Aug 2006 01:09:10 -0400 Received: from gateway.insightbb.com ([74.128.0.19]:8722 "EHLO asav08.manage.insightbb.com") by vger.kernel.org with ESMTP id S1751512AbWHKFJD (ORCPT ); Fri, 11 Aug 2006 01:09:03 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AQAAAI+t20QN Message-Id: <20060811050611.530817371.dtor@insightbb.com> References: <20060811050310.958962036.dtor@insightbb.com> Date: Fri, 11 Aug 2006 01:03:15 -0400 From: Dmitry Torokhov To: Richard Purdie Cc: LKML Subject: [patch 5/6] Convert to use mutexes instead of semaphores Content-Disposition: inline; filename=backlight-sem-to-mutex.patch Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 10713 Lines: 418 Backlight: convert to use mutexes instead of semaphores Signed-off-by: Dmitry Torokhov --- drivers/video/backlight/backlight.c | 89 +++++++++++++++++++++++------------- drivers/video/backlight/lcd.c | 73 +++++++++++++++++++++-------- include/linux/backlight.h | 2 include/linux/lcd.h | 2 4 files changed, 112 insertions(+), 54 deletions(-) Index: work/drivers/video/backlight/backlight.c =================================================================== --- work.orig/drivers/video/backlight/backlight.c +++ work/drivers/video/backlight/backlight.c @@ -16,20 +16,23 @@ static ssize_t backlight_show_power(struct class_device *cdev, char *buf) { - int rc = -ENXIO; + int rc; struct backlight_device *bd = to_backlight_device(cdev); - down(&bd->sem); - if (bd->props) - rc = sprintf(buf, "%d\n", bd->props->power); - up(&bd->sem); + rc = mutex_lock_interruptible(&bd->mutex); + if (rc) + return rc; + + rc = bd->props ? sprintf(buf, "%d\n", bd->props->power) : -ENXIO; + + mutex_unlock(&bd->mutex); return rc; } static ssize_t backlight_store_power(struct class_device *cdev, const char *buf, size_t count) { - int rc = -ENXIO; + int rc; char *endp; struct backlight_device *bd = to_backlight_device(cdev); int power = simple_strtoul(buf, &endp, 0); @@ -40,35 +43,43 @@ static ssize_t backlight_store_power(str if (size != count) return -EINVAL; - down(&bd->sem); + rc = mutex_lock_interruptible(&bd->mutex); + if (rc) + return rc; + if (bd->props) { pr_debug("backlight: set power to %d\n", power); bd->props->power = power; if (bd->props->update_status) bd->props->update_status(bd); rc = count; - } - up(&bd->sem); + } else + rc = -ENXIO; + + mutex_unlock(&bd->mutex); return rc; } static ssize_t backlight_show_brightness(struct class_device *cdev, char *buf) { - int rc = -ENXIO; + int rc; struct backlight_device *bd = to_backlight_device(cdev); - down(&bd->sem); - if (bd->props) - rc = sprintf(buf, "%d\n", bd->props->brightness); - up(&bd->sem); + rc = mutex_lock_interruptible(&bd->mutex); + if (rc) + return rc; + + rc = bd->props ? sprintf(buf, "%d\n", bd->props->brightness) : -ENXIO; + + mutex_unlock(&bd->mutex); return rc; } static ssize_t backlight_store_brightness(struct class_device *cdev, const char *buf, size_t count) { - int rc = -ENXIO; + int rc; char *endp; struct backlight_device *bd = to_backlight_device(cdev); int brightness = simple_strtoul(buf, &endp, 0); @@ -79,7 +90,10 @@ static ssize_t backlight_store_brightnes if (size != count) return -EINVAL; - down(&bd->sem); + rc = mutex_lock_interruptible(&bd->mutex); + if (rc) + return rc; + if (bd->props) { if (brightness > bd->props->max_brightness) rc = -EINVAL; @@ -91,21 +105,26 @@ static ssize_t backlight_store_brightnes bd->props->update_status(bd); rc = count; } - } - up(&bd->sem); + } else + rc = -ENXIO; + + mutex_unlock(&bd->mutex); return rc; } static ssize_t backlight_show_max_brightness(struct class_device *cdev, char *buf) { - int rc = -ENXIO; + int rc; struct backlight_device *bd = to_backlight_device(cdev); - down(&bd->sem); - if (bd->props) - rc = sprintf(buf, "%d\n", bd->props->max_brightness); - up(&bd->sem); + rc = mutex_lock_interruptible(&bd->mutex); + if (rc) + return rc; + + rc = bd->props ? sprintf(buf, "%d\n", bd->props->max_brightness) : -ENXIO; + + mutex_unlock(&bd->mutex); return rc; } @@ -113,13 +132,19 @@ static ssize_t backlight_show_max_bright static ssize_t backlight_show_actual_brightness(struct class_device *cdev, char *buf) { - int rc = -ENXIO; + int rc; struct backlight_device *bd = to_backlight_device(cdev); - down(&bd->sem); + rc = mutex_lock_interruptible(&bd->mutex); + if (rc) + return rc; + if (bd->props && bd->props->get_brightness) rc = sprintf(buf, "%d\n", bd->props->get_brightness(bd)); - up(&bd->sem); + else + rc = -ENXIO; + + mutex_unlock(&bd->mutex); return rc; } @@ -161,7 +186,8 @@ static int fb_notifier_callback(struct n return 0; bd = container_of(self, struct backlight_device, fb_notif); - down(&bd->sem); + + mutex_lock(&bd->mutex); if (bd->props) { if (!bd->props->check_fb || bd->props->check_fb(evdata->info)) { @@ -170,7 +196,8 @@ static int fb_notifier_callback(struct n bd->props->update_status(bd); } } - up(&bd->sem); + mutex_unlock(&bd->mutex); + return 0; } @@ -198,7 +225,7 @@ struct backlight_device *backlight_devic if (!new_bd) return ERR_PTR(-ENOMEM); - init_MUTEX(&new_bd->sem); + mutex_init(&new_bd->mutex); new_bd->props = bp; new_bd->class_dev.class = &backlight_class; strlcpy(new_bd->class_dev.class_id, name, KOBJ_NAME_LEN); @@ -235,7 +262,7 @@ void backlight_device_unregister(struct pr_debug("backlight_device_unregister: name=%s\n", bd->class_dev.class_id); - down(&bd->sem); + mutex_lock(&bd->mutex); if (bd->props && bd->props->update_status) { bd->props->brightness = 0; bd->props->power = 0; @@ -243,7 +270,7 @@ void backlight_device_unregister(struct } bd->props = NULL; - up(&bd->sem); + mutex_unlock(&bd->mutex); fb_unregister_client(&bd->fb_notif); class_device_unregister(&bd->class_dev); Index: work/drivers/video/backlight/lcd.c =================================================================== --- work.orig/drivers/video/backlight/lcd.c +++ work/drivers/video/backlight/lcd.c @@ -16,20 +16,26 @@ static ssize_t lcd_show_power(struct class_device *cdev, char *buf) { - int rc = -ENXIO; + int rc; struct lcd_device *ld = to_lcd_device(cdev); - down(&ld->sem); + rc = mutex_lock_interruptible(&ld->mutex); + if (rc) + return rc; + if (ld->props && ld->props->get_power) rc = sprintf(buf, "%d\n", ld->props->get_power(ld)); - up(&ld->sem); + else + rc = -ENXIO; + + mutex_unlock(&ld->mutex); return rc; } static ssize_t lcd_store_power(struct class_device *cdev, const char *buf, size_t count) { - int rc = -ENXIO; + int rc; char *endp; struct lcd_device *ld = to_lcd_device(cdev); int power = simple_strtoul(buf, &endp, 0); @@ -40,33 +46,44 @@ static ssize_t lcd_store_power(struct cl if (size != count) return -EINVAL; - down(&ld->sem); + rc = mutex_lock_interruptible(&ld->mutex); + if (rc) + return rc; + if (ld->props && ld->props->set_power) { pr_debug("lcd: set power to %d\n", power); ld->props->set_power(ld, power); rc = count; - } - up(&ld->sem); + } else + rc = -ENXIO; + + mutex_unlock(&ld->mutex); return rc; } static ssize_t lcd_show_contrast(struct class_device *cdev, char *buf) { - int rc = -ENXIO; + int rc; struct lcd_device *ld = to_lcd_device(cdev); - down(&ld->sem); + rc = mutex_lock_interruptible(&ld->mutex); + if (rc) + return rc; + if (ld->props && ld->props->get_contrast) rc = sprintf(buf, "%d\n", ld->props->get_contrast(ld)); - up(&ld->sem); + else + rc = -ENXIO; + + mutex_unlock(&ld->mutex); return rc; } static ssize_t lcd_store_contrast(struct class_device *cdev, const char *buf, size_t count) { - int rc = -ENXIO; + int rc; char *endp; struct lcd_device *ld = to_lcd_device(cdev); int contrast = simple_strtoul(buf, &endp, 0); @@ -77,13 +94,18 @@ static ssize_t lcd_store_contrast(struct if (size != count) return -EINVAL; - down(&ld->sem); + rc = mutex_lock_interruptible(&ld->mutex); + if (rc) + return rc; + if (ld->props && ld->props->set_contrast) { pr_debug("lcd: set contrast to %d\n", contrast); ld->props->set_contrast(ld, contrast); rc = count; - } - up(&ld->sem); + } else + rc = -ENXIO; + + mutex_unlock(&ld->mutex); return rc; } @@ -93,10 +115,16 @@ static ssize_t lcd_show_max_contrast(str int rc = -ENXIO; struct lcd_device *ld = to_lcd_device(cdev); - down(&ld->sem); + rc = mutex_lock_interruptible(&ld->mutex); + if (rc) + return rc; + if (ld->props) rc = sprintf(buf, "%d\n", ld->props->max_contrast); - up(&ld->sem); + else + rc = -ENXIO; + + mutex_unlock(&ld->mutex); return rc; } @@ -104,6 +132,7 @@ static ssize_t lcd_show_max_contrast(str static void lcd_class_release(struct class_device *dev) { struct lcd_device *ld = to_lcd_device(dev); + kfree(ld); } @@ -135,11 +164,13 @@ static int fb_notifier_callback(struct n return 0; ld = container_of(self, struct lcd_device, fb_notif); - down(&ld->sem); + + mutex_lock(&ld->mutex); if (ld->props) if (!ld->props->check_fb || ld->props->check_fb(evdata->info)) ld->props->set_power(ld, *(int *)evdata->data); - up(&ld->sem); + mutex_unlock(&ld->mutex); + return 0; } @@ -166,7 +197,7 @@ struct lcd_device *lcd_device_register(c if (!new_ld) return ERR_PTR(-ENOMEM); - init_MUTEX(&new_ld->sem); + mutex_init(&new_ld->mutex); new_ld->props = lp; new_ld->class_dev.class = &lcd_class; strlcpy(new_ld->class_dev.class_id, name, KOBJ_NAME_LEN); @@ -203,9 +234,9 @@ void lcd_device_unregister(struct lcd_de pr_debug("lcd_device_unregister: name=%s\n", ld->class_dev.class_id); - down(&ld->sem); + mutex_lock(&ld->mutex); ld->props = NULL; - up(&ld->sem); + mutex_unlock(&ld->mutex); fb_unregister_client(&ld->fb_notif); class_device_unregister(&ld->class_dev); Index: work/include/linux/backlight.h =================================================================== --- work.orig/include/linux/backlight.h +++ work/include/linux/backlight.h @@ -41,7 +41,7 @@ struct backlight_device { /* This protects the 'props' field. If 'props' is NULL, the driver that registered this device has been unloaded, and if class_get_devdata() points to something in the body of that driver, it is also invalid. */ - struct semaphore sem; + struct mutex mutex; /* If this is NULL, the backing module is unloaded */ struct backlight_properties *props; /* The framebuffer notifier block */ Index: work/include/linux/lcd.h =================================================================== --- work.orig/include/linux/lcd.h +++ work/include/linux/lcd.h @@ -36,7 +36,7 @@ struct lcd_device { /* This protects the 'props' field. If 'props' is NULL, the driver that registered this device has been unloaded, and if class_get_devdata() points to something in the body of that driver, it is also invalid. */ - struct semaphore sem; + struct mutex mutex; /* If this is NULL, the backing module is unloaded */ struct lcd_properties *props; /* The framebuffer notifier block */ - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/