Input: uinput - use completions instead of events and manual

       wakeups in force feedback code.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c
index 9c3d200..c3eebf5 100644 (file)
--- a/drivers/input/misc/uinput.c
+++ b/drivers/input/misc/uinput.c
@@ -53,24 +53,23 @@ static int uinput_dev_event(struct input_dev *dev, unsigned int type, unsigned i
        return 0;
 }
 
-static int uinput_request_alloc_id(struct input_dev *dev, struct uinput_request *request)
+static int uinput_request_alloc_id(struct uinput_device *udev, struct uinput_request *request)
 {
        /* Atomically allocate an ID for the given request. Returns 0 on success. */
-       struct uinput_device *udev = dev->private;
        int id;
        int err = -1;
 
-       down(&udev->requests_sem);
+       spin_lock(&udev->requests_lock);
 
        for (id = 0; id < UINPUT_NUM_REQUESTS; id++)
                if (!udev->requests[id]) {
-                       udev->requests[id] = request;
                        request->id = id;
+                       udev->requests[id] = request;
                        err = 0;
                        break;
                }
 
-       up(&udev->requests_sem);
+       spin_unlock(&udev->requests_lock);
        return err;
 }
 
@@ -79,70 +78,78 @@ static struct uinput_request* uinput_request_find(struct uinput_device *udev, in
        /* Find an input request, by ID. Returns NULL if the ID isn't valid. */
        if (id >= UINPUT_NUM_REQUESTS || id < 0)
                return NULL;
-       if (udev->requests[id]->completed)
-               return NULL;
        return udev->requests[id];
 }
 
-static void uinput_request_init(struct input_dev *dev, struct uinput_request *request, int code)
+static inline int uinput_request_reserve_slot(struct uinput_device *udev, struct uinput_request *request)
 {
-       struct uinput_device *udev = dev->private;
+       /* Allocate slot. If none are available right away, wait. */
+       return wait_event_interruptible(udev->requests_waitq,
+                                       !uinput_request_alloc_id(udev, request));
+}
 
-       memset(request, 0, sizeof(struct uinput_request));
-       request->code = code;
-       init_waitqueue_head(&request->waitq);
+static void uinput_request_done(struct uinput_device *udev, struct uinput_request *request)
+{
+       complete(&request->done);
 
-       /* Allocate an ID. If none are available right away, wait. */
-       request->retval = wait_event_interruptible(udev->requests_waitq,
-                                       !uinput_request_alloc_id(dev, request));
+       /* Mark slot as available */
+       udev->requests[request->id] = NULL;
+       wake_up_interruptible(&udev->requests_waitq);
 }
 
-static void uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
+static int uinput_request_submit(struct input_dev *dev, struct uinput_request *request)
 {
-       struct uinput_device *udev = dev->private;
        int retval;
 
        /* Tell our userspace app about this new request by queueing an input event */
        uinput_dev_event(dev, EV_UINPUT, request->code, request->id);
 
        /* Wait for the request to complete */
-       retval = wait_event_interruptible(request->waitq, request->completed);
-       if (retval)
-               request->retval = retval;
+       retval = wait_for_completion_interruptible(&request->done);
+       if (!retval)
+               retval = request->retval;
 
-       /* Release this request's ID, let others know it's available */
-       udev->requests[request->id] = NULL;
-       wake_up_interruptible(&udev->requests_waitq);
+       return retval;
 }
 
 static int uinput_dev_upload_effect(struct input_dev *dev, struct ff_effect *effect)
 {
        struct uinput_request request;
+       int retval;
 
        if (!test_bit(EV_FF, dev->evbit))
                return -ENOSYS;
 
-       uinput_request_init(dev, &request, UI_FF_UPLOAD);
-       if (request.retval)
-               return request.retval;
+       request.id = -1;
+       init_completion(&request.done);
+       request.code = UI_FF_UPLOAD;
        request.u.effect = effect;
-       uinput_request_submit(dev, &request);
-       return request.retval;
+
+       retval = uinput_request_reserve_slot(dev->private, &request);
+       if (!retval)
+               retval = uinput_request_submit(dev, &request);
+
+       return retval;
 }
 
 static int uinput_dev_erase_effect(struct input_dev *dev, int effect_id)
 {
        struct uinput_request request;
+       int retval;
 
        if (!test_bit(EV_FF, dev->evbit))
                return -ENOSYS;
 
-       uinput_request_init(dev, &request, UI_FF_ERASE);
-       if (request.retval)
-               return request.retval;
+       request.id = -1;
+       init_completion(&request.done);
+       request.code = UI_FF_ERASE;
        request.u.effect_id = effect_id;
-       uinput_request_submit(dev, &request);
-       return request.retval;
+
+       retval = uinput_request_reserve_slot(dev->private, &request);
+       if (!retval)
+               retval = uinput_request_submit(dev, &request);
+
+       return retval;
 }
 
 static int uinput_create_device(struct uinput_device *udev)
@@ -189,7 +196,7 @@ static int uinput_open(struct inode *inode, struct file *file)
        if (!newdev)
                goto error;
        memset(newdev, 0, sizeof(struct uinput_device));
-       init_MUTEX(&newdev->requests_sem);
+       spin_lock_init(&newdev->requests_lock);
        init_waitqueue_head(&newdev->requests_waitq);
 
        newinput = kmalloc(sizeof(struct input_dev), GFP_KERNEL);
@@ -551,8 +558,7 @@ static int uinput_ioctl(struct inode *inode, struct file *file, unsigned int cmd
                        }
                        req->retval = ff_up.retval;
                        memcpy(req->u.effect, &ff_up.effect, sizeof(struct ff_effect));
-                       req->completed = 1;
-                       wake_up_interruptible(&req->waitq);
+                       uinput_request_done(udev, req);
                        break;
 
                case UI_END_FF_ERASE:
@@ -566,8 +572,7 @@ static int uinput_ioctl(struct inode *inode, struct file *file, unsigned int cmd
                                break;
                        }
                        req->retval = ff_erase.retval;
-                       req->completed = 1;
-                       wake_up_interruptible(&req->waitq);
+                       uinput_request_done(udev, req);
                        break;
 
                default:

diff --git a/include/linux/uinput.h b/include/linux/uinput.h
index 4c2c823..8487607 100644 (file)
--- a/include/linux/uinput.h
+++ b/include/linux/uinput.h
@@ -42,8 +42,7 @@ struct uinput_request {
        int                     code;   /* UI_FF_UPLOAD, UI_FF_ERASE */
 
        int                     retval;
-       wait_queue_head_t       waitq;
-       int                     completed;
+       struct completion       done;
 
        union {
                int             effect_id;
@@ -62,7 +61,7 @@ struct uinput_device {
 
        struct uinput_request   *requests[UINPUT_NUM_REQUESTS];
        wait_queue_head_t       requests_waitq;
-       struct semaphore        requests_sem;
+       spinlock_t              requests_lock;
 };
 #endif /* __KERNEL__ */