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authorHenrik Rydberg <rydberg@euromail.se>2010-06-23 09:17:56 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2010-06-23 13:04:42 -0700
commitb58f7086d52c0ac6c879ee5aaf7c276e17768e5b (patch)
treeb4dc1d1b516f36bdf5cda18af3a8a28d5706068a /drivers/input/evdev.c
parent4aaf504670e38da9cb929988cdce05648fa635a7 (diff)
Input: evdev - convert to dynamic event buffer
Allocate the event buffer dynamically, and prepare to compute the buffer size in a separate function. This patch defines the size computation to be identical to the current code, and does not contain any logical changes. Signed-off-by: Henrik Rydberg <rydberg@euromail.se> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Diffstat (limited to 'drivers/input/evdev.c')
-rw-r--r--drivers/input/evdev.c22
1 files changed, 17 insertions, 5 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 2ee6c7a68bd..cff7bf9351a 100644
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -10,7 +10,7 @@
#define EVDEV_MINOR_BASE 64
#define EVDEV_MINORS 32
-#define EVDEV_BUFFER_SIZE 64
+#define EVDEV_MIN_BUFFER_SIZE 64
#include <linux/poll.h>
#include <linux/sched.h>
@@ -36,13 +36,14 @@ struct evdev {
};
struct evdev_client {
- struct input_event buffer[EVDEV_BUFFER_SIZE];
int head;
int tail;
spinlock_t buffer_lock; /* protects access to buffer, head and tail */
struct fasync_struct *fasync;
struct evdev *evdev;
struct list_head node;
+ int bufsize;
+ struct input_event buffer[];
};
static struct evdev *evdev_table[EVDEV_MINORS];
@@ -56,7 +57,7 @@ static void evdev_pass_event(struct evdev_client *client,
*/
spin_lock(&client->buffer_lock);
client->buffer[client->head++] = *event;
- client->head &= EVDEV_BUFFER_SIZE - 1;
+ client->head &= client->bufsize - 1;
spin_unlock(&client->buffer_lock);
if (event->type == EV_SYN)
@@ -242,11 +243,17 @@ static int evdev_release(struct inode *inode, struct file *file)
return 0;
}
+static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
+{
+ return EVDEV_MIN_BUFFER_SIZE;
+}
+
static int evdev_open(struct inode *inode, struct file *file)
{
struct evdev *evdev;
struct evdev_client *client;
int i = iminor(inode) - EVDEV_MINOR_BASE;
+ unsigned int bufsize;
int error;
if (i >= EVDEV_MINORS)
@@ -263,12 +270,17 @@ static int evdev_open(struct inode *inode, struct file *file)
if (!evdev)
return -ENODEV;
- client = kzalloc(sizeof(struct evdev_client), GFP_KERNEL);
+ bufsize = evdev_compute_buffer_size(evdev->handle.dev);
+
+ client = kzalloc(sizeof(struct evdev_client) +
+ bufsize * sizeof(struct input_event),
+ GFP_KERNEL);
if (!client) {
error = -ENOMEM;
goto err_put_evdev;
}
+ client->bufsize = bufsize;
spin_lock_init(&client->buffer_lock);
client->evdev = evdev;
evdev_attach_client(evdev, client);
@@ -334,7 +346,7 @@ static int evdev_fetch_next_event(struct evdev_client *client,
have_event = client->head != client->tail;
if (have_event) {
*event = client->buffer[client->tail++];
- client->tail &= EVDEV_BUFFER_SIZE - 1;
+ client->tail &= client->bufsize - 1;
}
spin_unlock_irq(&client->buffer_lock);