From 0048e6030d41453c2f5ce0e9aead910d46cfd448 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Thu, 30 Jun 2005 00:48:14 -0500 Subject: [PATCH] Input: uinput - use completions instead of events and manual wakeups in force feedback code. Signed-off-by: Dmitry Torokhov --- drivers/input/misc/uinput.c | 81 ++++++++++++++++++++----------------- include/linux/uinput.h | 5 +-- 2 files changed, 45 insertions(+), 41 deletions(-) diff --git a/drivers/input/misc/uinput.c b/drivers/input/misc/uinput.c index 9c3d20073ae3..c3eebf593ab6 100644 --- 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 4c2c82336d10..84876077027f 100644 --- 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__ */ -- 2.30.2