PM: Enable partial support for FB earlysuspend
Prashant Gaikwad [Wed, 25 Apr 2012 05:51:40 +0000 (10:51 +0530)]
In absence of sysfs entries for FB early suspend
DisplayEventThread keeps looping which prevents CPUs
from entering in LP2 idle state.

Bug 959487
Bug 971668

Change-Id: I575077fe3baa6e22548c7fc838f6f122c5afdc47
Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Reviewed-on: http://git-master/r/98642
Reviewed-by: Nitin Kumbhar <nkumbhar@nvidia.com>
Reviewed-by: Varun Wadekar <vwadekar@nvidia.com>

kernel/power/Makefile
kernel/power/fbearlysuspend.c [new file with mode: 0644]

index 7f51f84..06f9472 100644 (file)
@@ -12,4 +12,5 @@ obj-$(CONFIG_HIBERNATION)     += hibernate.o snapshot.o swap.o user.o \
 obj-$(CONFIG_USER_WAKELOCK)    += userwakelock.o
 obj-$(CONFIG_SUSPEND_TIME)     += suspend_time.o
 
+obj-y   += fbearlysuspend.o
 obj-$(CONFIG_MAGIC_SYSRQ)      += poweroff.o
diff --git a/kernel/power/fbearlysuspend.c b/kernel/power/fbearlysuspend.c
new file mode 100644 (file)
index 0000000..571b51a
--- /dev/null
@@ -0,0 +1,114 @@
+/* kernel/power/fbearlysuspend.c
+ *
+ * Copyright (C) 2005-2008 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/wait.h>
+
+#include "power.h"
+
+static wait_queue_head_t fb_state_wq;
+static DEFINE_SPINLOCK(fb_state_lock);
+static enum {
+       FB_STATE_STOPPED_DRAWING,
+       FB_STATE_REQUEST_STOP_DRAWING,
+       FB_STATE_DRAWING_OK,
+} fb_state;
+
+static ssize_t wait_for_fb_sleep_show(struct kobject *kobj,
+                                     struct kobj_attribute *attr, char *buf)
+{
+       char *s = buf;
+       int ret;
+
+       ret = wait_event_interruptible(fb_state_wq,
+                                      fb_state != FB_STATE_DRAWING_OK);
+       if (ret && fb_state == FB_STATE_DRAWING_OK)
+               return ret;
+       else
+               s += sprintf(buf, "sleeping");
+       return s - buf;
+}
+
+static ssize_t wait_for_fb_wake_show(struct kobject *kobj,
+                                    struct kobj_attribute *attr, char *buf)
+{
+       char *s = buf;
+       int ret;
+       unsigned long irq_flags;
+
+       spin_lock_irqsave(&fb_state_lock, irq_flags);
+       if (fb_state == FB_STATE_REQUEST_STOP_DRAWING) {
+               fb_state = FB_STATE_STOPPED_DRAWING;
+               wake_up(&fb_state_wq);
+       }
+       spin_unlock_irqrestore(&fb_state_lock, irq_flags);
+
+       ret = wait_event_interruptible(fb_state_wq,
+                                      fb_state == FB_STATE_DRAWING_OK);
+       if (ret && fb_state != FB_STATE_DRAWING_OK)
+               return ret;
+       else
+               s += sprintf(buf, "awake");
+
+       return s - buf;
+}
+
+#define power_ro_attr(_name) \
+static struct kobj_attribute _name##_attr = {  \
+       .attr   = {                             \
+               .name = __stringify(_name),     \
+               .mode = 0444,                   \
+       },                                      \
+       .show   = _name##_show,                 \
+       .store  = NULL,         \
+}
+
+power_ro_attr(wait_for_fb_sleep);
+power_ro_attr(wait_for_fb_wake);
+
+static struct attribute *g[] = {
+       &wait_for_fb_sleep_attr.attr,
+       &wait_for_fb_wake_attr.attr,
+       NULL,
+};
+
+static struct attribute_group attr_group = {
+       .attrs = g,
+};
+
+static int __init android_power_init(void)
+{
+       int ret;
+
+       init_waitqueue_head(&fb_state_wq);
+       fb_state = FB_STATE_DRAWING_OK;
+
+       ret = sysfs_create_group(power_kobj, &attr_group);
+       if (ret) {
+               pr_err("android_power_init: sysfs_create_group failed\n");
+               return ret;
+       }
+
+       return 0;
+}
+
+static void  __exit android_power_exit(void)
+{
+       sysfs_remove_group(power_kobj, &attr_group);
+}
+
+module_init(android_power_init);
+module_exit(android_power_exit);
+