Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq

[sfrench/cifs-2.6.git] / drivers / input / evdev.c

diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
index 2ee6c7a68bdccf4c9cf6c330f824d341f0a69302..054edf346e0b5f060e352572f473244e4aeeadcb 100644 (file)
--- a/drivers/input/evdev.c
+++ b/drivers/input/evdev.c
@@ -10,7 +10,8 @@
 
 #define EVDEV_MINOR_BASE       64
 #define EVDEV_MINORS           32
-#define EVDEV_BUFFER_SIZE      64
+#define EVDEV_MIN_BUFFER_SIZE  64U
+#define EVDEV_BUF_PACKETS      8
 
 #include <linux/poll.h>
 #include <linux/sched.h>
@@ -23,7 +24,6 @@
 #include "input-compat.h"
 
 struct evdev {
-       int exist;
        int open;
        int minor;
        struct input_handle handle;
@@ -33,16 +33,18 @@ struct evdev {
        spinlock_t client_lock; /* protects client_list */
        struct mutex mutex;
        struct device dev;
+       bool exist;
 };
 
 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];
@@ -52,11 +54,15 @@ static void evdev_pass_event(struct evdev_client *client,
                             struct input_event *event)
 {
        /*
-        * Interrupts are disabled, just acquire the lock
+        * Interrupts are disabled, just acquire the lock.
+        * Make sure we don't leave with the client buffer
+        * "empty" by having client->head == client->tail.
         */
        spin_lock(&client->buffer_lock);
-       client->buffer[client->head++] = *event;
-       client->head &= EVDEV_BUFFER_SIZE - 1;
+       do {
+               client->buffer[client->head++] = *event;
+               client->head &= client->bufsize - 1;
+       } while (client->head == client->tail);
        spin_unlock(&client->buffer_lock);
 
        if (event->type == EV_SYN)
@@ -242,11 +248,21 @@ static int evdev_release(struct inode *inode, struct file *file)
        return 0;
 }
 
+static unsigned int evdev_compute_buffer_size(struct input_dev *dev)
+{
+       unsigned int n_events =
+               max(dev->hint_events_per_packet * EVDEV_BUF_PACKETS,
+                   EVDEV_MIN_BUFFER_SIZE);
+
+       return roundup_pow_of_two(n_events);
+}
+
 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 +279,17 @@ 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 +355,7 @@ 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);
@@ -382,10 +403,15 @@ static unsigned int evdev_poll(struct file *file, poll_table *wait)
 {
        struct evdev_client *client = file->private_data;
        struct evdev *evdev = client->evdev;
+       unsigned int mask;
 
        poll_wait(file, &evdev->wait, wait);
-       return ((client->head == client->tail) ? 0 : (POLLIN | POLLRDNORM)) |
-               (evdev->exist ? 0 : (POLLHUP | POLLERR));
+
+       mask = evdev->exist ? POLLOUT | POLLWRNORM : POLLHUP | POLLERR;
+       if (client->head != client->tail)
+               mask |= POLLIN | POLLRDNORM;
+
+       return mask;
 }
 
 #ifdef CONFIG_COMPAT
@@ -665,6 +691,10 @@ static long evdev_do_ioctl(struct file *file, unsigned int cmd,
                                                                  sizeof(struct input_absinfo))))
                                        return -EFAULT;
 
+                               /* We can't change number of reserved MT slots */
+                               if (t == ABS_MT_SLOT)
+                                       return -EINVAL;
+
                                /*
                                 * Take event lock to ensure that we are not
                                 * changing device parameters in the middle
@@ -768,7 +798,7 @@ static void evdev_remove_chrdev(struct evdev *evdev)
 static void evdev_mark_dead(struct evdev *evdev)
 {
        mutex_lock(&evdev->mutex);
-       evdev->exist = 0;
+       evdev->exist = false;
        mutex_unlock(&evdev->mutex);
 }
 
@@ -817,7 +847,7 @@ static int evdev_connect(struct input_handler *handler, struct input_dev *dev,
        init_waitqueue_head(&evdev->wait);
 
        dev_set_name(&evdev->dev, "event%d", minor);
-       evdev->exist = 1;
+       evdev->exist = true;
        evdev->minor = minor;
 
        evdev->handle.dev = input_get_device(dev);