target/linux/s3c24xx/patches-2.6.26/1050-fix-EVIOCGRAB-semantics.patch.patch

   1 From 6294c84872b0d26111bdd1b9e5fec41c8a087443 Mon Sep 17 00:00:00 2001
   2 From: mokopatches <mokopatches@openmoko.org>
   3 Date: Fri, 25 Jul 2008 22:21:23 +0100
   4 Subject: [PATCH] fix-EVIOCGRAB-semantics.patch
   5
   6 ---
   7  drivers/input/evdev.c |   32 +++++++++++++++-----------------
   8  1 files changed, 15 insertions(+), 17 deletions(-)
   9
  10 diff --git a/drivers/input/evdev.c b/drivers/input/evdev.c
  11 index b32984b..499ffe1 100644
  12 --- a/drivers/input/evdev.c
  13 +++ b/drivers/input/evdev.c
  14 @@ -28,7 +28,7 @@ struct evdev {
  15         char name[16];
  16         struct input_handle handle;
  17         wait_queue_head_t wait;
  18 -       struct evdev_client *grab;
  19 +       int *grab;
  20         struct list_head client_list;
  21         spinlock_t client_lock; /* protects client_list */
  22         struct mutex mutex;
  23 @@ -39,6 +39,7 @@ struct evdev_client {
  24         struct input_event buffer[EVDEV_BUFFER_SIZE];
  25         int head;
  26         int tail;
  27 +       int grab;
  28         spinlock_t buffer_lock; /* protects access to buffer, head and tail */
  29         struct fasync_struct *fasync;
  30         struct evdev *evdev;
  31 @@ -79,12 +80,8 @@ static void evdev_event(struct input_handle *handle,
  32
  33         rcu_read_lock();
  34
  35 -       client = rcu_dereference(evdev->grab);
  36 -       if (client)
  37 +       list_for_each_entry_rcu(client, &evdev->client_list, node)
  38                 evdev_pass_event(client, &event);
  39 -       else
  40 -               list_for_each_entry_rcu(client, &evdev->client_list, node)
  41 -                       evdev_pass_event(client, &event);
  42
  43         rcu_read_unlock();
  44
  45 @@ -136,14 +133,15 @@ static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
  46  {
  47         int error;
  48
  49 -       if (evdev->grab)
  50 +       if (client->grab)
  51                 return -EBUSY;
  52
  53 -       error = input_grab_device(&evdev->handle);
  54 -       if (error)
  55 -               return error;
  56 -
  57 -       rcu_assign_pointer(evdev->grab, client);
  58 +       if (!evdev->grab++) {
  59 +           error = input_grab_device(&evdev->handle);
  60 +           if (error)
  61 +                   return error;
  62 +       }
  63 +       client->grab = 1;
  64         synchronize_rcu();
  65
  66         return 0;
  67 @@ -151,12 +149,12 @@ static int evdev_grab(struct evdev *evdev, struct evdev_client *client)
  68
  69  static int evdev_ungrab(struct evdev *evdev, struct evdev_client *client)
  70  {
  71 -       if (evdev->grab != client)
  72 +       if (!client->grab)
  73                 return  -EINVAL;
  74
  75 -       rcu_assign_pointer(evdev->grab, NULL);
  76 -       synchronize_rcu();
  77 -       input_release_device(&evdev->handle);
  78 +       if (!--evdev->grab && evdev->exist)
  79 +               input_release_device(&evdev->handle);
  80 +       client->grab = 0;
  81
  82         return 0;
  83  }
  84 @@ -231,7 +229,7 @@ static int evdev_release(struct inode *inode, struct file *file)
  85         struct evdev *evdev = client->evdev;
  86
  87         mutex_lock(&evdev->mutex);
  88 -       if (evdev->grab == client)
  89 +       if (client->grab)
  90                 evdev_ungrab(evdev, client);
  91         mutex_unlock(&evdev->mutex);
  92
  93 --
  94 1.5.6.3
  95