[PATCH 12/13] Input: Hold wake lock while event queue is not empty.

Arve Hjønnevåg
2009-02-05T02:50:25Z

Allows userspace code to process input events while
the device appears to be asleep.

Signed-off-by: Arve Hjønnevåg <arve@android.com>
---
drivers/input/evdev.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index ed8baa0..e24050b 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -19,6 +19,7 @@
#include <linux/input.h>
#include <linux/major.h>
#include <linux/device.h>
+#include <linux/wakelock.h>
#include "input-compat.h"

struct evdev {
@@ -43,6 +44,7 @@ struct evdev_client {
struct fasync_struct *fasync;
struct evdev *evdev;
struct list_head node;
+ struct wake_lock wake_lock;
};

static struct evdev *evdev_table[EVDEV_MINORS];
@@ -55,6 +57,7 @@ static void evdev_pass_event(struct evdev_client *client,
* Interrupts are disabled, just acquire the lock
*/
spin_lock(&client->buffer_lock);
+ wake_lock_timeout(&client->wake_lock, 5 * HZ);
client->buffer[client->head++] = *event;
client->head &= EVDEV_BUFFER_SIZE - 1;
spin_unlock(&client->buffer_lock);
@@ -236,6 +239,7 @@ static int evdev_release(struct inode *inode, struct file *file)
mutex_unlock(&evdev->mutex);

evdev_detach_client(evdev, client);
+ wake_lock_destroy(&client->wake_lock);
kfree(client);

evdev_close_device(evdev);
@@ -272,6 +276,7 @@ static int evdev_open(struct inode *inode, struct file *file)
}

spin_lock_init(&client->buffer_lock);
+ wake_lock_init(&client->wake_lock, WAKE_LOCK_SUSPEND, "evdev");
client->evdev = evdev;
evdev_attach_client(evdev, client);

@@ -335,6 +340,8 @@ static int evdev_fetch_next_event(struct evdev_client *client,
if (have_event) {
*event = client->buffer[client->tail++];
client->tail &= EVDEV_BUFFER_SIZE - 1;
+ if (client->head == client->tail)
+ wake_unlock(&client->wake_lock);
}

spin_unlock_irq(&client->buffer_lock);
--
1.6.1

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