Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752999Ab2JIGDO (ORCPT ); Tue, 9 Oct 2012 02:03:14 -0400 Received: from mail-qa0-f46.google.com ([209.85.216.46]:49201 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752827Ab2JIGDC (ORCPT ); Tue, 9 Oct 2012 02:03:02 -0400 From: Len Brown To: linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Zhang Rui Subject: [PATCH 13/30] Thermal: Introduce locking for cdev.thermal_instances list. Date: Tue, 9 Oct 2012 01:54:03 -0400 Message-Id: X-Mailer: git-send-email 1.8.0.rc1 In-Reply-To: <1349762060-25334-1-git-send-email-lenb@kernel.org> References: <1349762060-25334-1-git-send-email-lenb@kernel.org> In-Reply-To: References: Reply-To: Len Brown Organization: Intel Open Source Technology Center Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3482 Lines: 99 From: Zhang Rui we need to go over all the thermal_instance list of a cooling device to decide which cooling state to put the cooling device to. But at this time, as a cooling device may be referenced in multiple thermal zones, we need to lock the list first in case another thermal zone is updating this cooling device. Signed-off-by: Zhang Rui Reviewed-by: Rafael J. Wysocki Reviewed-by: Eduardo Valentin --- drivers/thermal/thermal_sys.c | 8 ++++++++ include/linux/thermal.h | 1 + 2 files changed, 9 insertions(+) diff --git a/drivers/thermal/thermal_sys.c b/drivers/thermal/thermal_sys.c index 6e9d3dc..5be8728 100644 --- a/drivers/thermal/thermal_sys.c +++ b/drivers/thermal/thermal_sys.c @@ -799,6 +799,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, goto remove_symbol_link; mutex_lock(&tz->lock); + mutex_lock(&cdev->lock); list_for_each_entry(pos, &tz->thermal_instances, tz_node) if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { result = -EEXIST; @@ -808,6 +809,7 @@ int thermal_zone_bind_cooling_device(struct thermal_zone_device *tz, list_add_tail(&dev->tz_node, &tz->thermal_instances); list_add_tail(&dev->cdev_node, &cdev->thermal_instances); } + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); if (!result) @@ -840,14 +842,17 @@ int thermal_zone_unbind_cooling_device(struct thermal_zone_device *tz, struct thermal_instance *pos, *next; mutex_lock(&tz->lock); + mutex_lock(&cdev->lock); list_for_each_entry_safe(pos, next, &tz->thermal_instances, tz_node) { if (pos->tz == tz && pos->trip == trip && pos->cdev == cdev) { list_del(&pos->tz_node); list_del(&pos->cdev_node); + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); goto unbind; } } + mutex_unlock(&cdev->lock); mutex_unlock(&tz->lock); return -ENODEV; @@ -913,6 +918,7 @@ thermal_cooling_device_register(char *type, void *devdata, } strcpy(cdev->type, type); + mutex_init(&cdev->lock); INIT_LIST_HEAD(&cdev->thermal_instances); cdev->ops = ops; cdev->updated = true; @@ -1016,6 +1022,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) if (cdev->updated) return; + mutex_lock(&cdev->lock); /* Make sure cdev enters the deepest cooling state */ list_for_each_entry(instance, &cdev->thermal_instances, cdev_node) { if (instance->target == THERMAL_NO_TARGET) @@ -1023,6 +1030,7 @@ static void thermal_cdev_do_update(struct thermal_cooling_device *cdev) if (instance->target > target) target = instance->target; } + mutex_unlock(&cdev->lock); cdev->ops->set_cur_state(cdev, target); cdev->updated = true; } diff --git a/include/linux/thermal.h b/include/linux/thermal.h index 76d0fe8..91b3481 100644 --- a/include/linux/thermal.h +++ b/include/linux/thermal.h @@ -95,6 +95,7 @@ struct thermal_cooling_device { void *devdata; const struct thermal_cooling_device_ops *ops; bool updated; /* true if the cooling device does not need update */ + struct mutex lock; /* protect thermal_instances list */ struct list_head thermal_instances; struct list_head node; }; -- 1.8.0.rc1 -- 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/