diff options
Diffstat (limited to 'drivers/input/evdev.c')
| -rw-r--r-- | drivers/input/evdev.c | 54 |
1 files changed, 42 insertions, 12 deletions
diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c index 2ee6c7a68bdc..054edf346e0b 100644 --- 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); |