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Input: evdev - convert to dynamic event buffer

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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>
This commit is contained in:
Henrik Rydberg 2010-06-23 09:17:56 -07:00 committed by Dmitry Torokhov
parent 4aaf504670
commit b58f7086d5
1 changed files with 17 additions and 5 deletions
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22
drivers/input/evdev.c
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@ -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);