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Commit b58f7086 authored by Henrik Rydberg's avatar Henrik Rydberg Committed by Dmitry Torokhov
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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: default avatarHenrik Rydberg <rydberg@euromail.se>
Signed-off-by: default avatarDmitry Torokhov <dtor@mail.ru>
parent 4aaf5046

drivers/input/evdev.c

+17 −5
Original line number Diff line number Diff line
@@ -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);