1 files changed, 15 insertions, 50 deletions

diff --git a/drivers/media/video/cpia2/cpia2_core.c b/drivers/media/video/cpia2/cpia2_core.c
index 9606bc01b803..aaffca8e13fd 100644
--- a/drivers/media/video/cpia2/cpia2_core.c
+++ b/drivers/media/video/cpia2/cpia2_core.c
@@ -2247,7 +2247,7 @@ struct camera_data *cpia2_init_camera_struct(void)
 
 
 	cam->present = 1;
-	mutex_init(&cam->busy_lock);
+	mutex_init(&cam->v4l2_lock);
 	init_waitqueue_head(&cam->wq_stream);
 
 	return cam;
@@ -2365,9 +2365,9 @@ long cpia2_read(struct camera_data *cam,
 		char __user *buf, unsigned long count, int noblock)
 {
 	struct framebuf *frame;
-	if (!count) {
+
+	if (!count)
 		return 0;
-	}
 
 	if (!buf) {
 		ERR("%s: buffer NULL\n",__func__);
@@ -2379,17 +2379,12 @@ long cpia2_read(struct camera_data *cam,
 		return -EINVAL;
 	}
 
-	/* make this _really_ smp and multithread-safe */
-	if (mutex_lock_interruptible(&cam->busy_lock))
-		return -ERESTARTSYS;
-
 	if (!cam->present) {
 		LOG("%s: camera removed\n",__func__);
-		mutex_unlock(&cam->busy_lock);
 		return 0;	/* EOF */
 	}
 
-	if(!cam->streaming) {
+	if (!cam->streaming) {
 		/* Start streaming */
 		cpia2_usb_stream_start(cam,
 				       cam->params.camera_state.stream_mode);
@@ -2398,42 +2393,31 @@ long cpia2_read(struct camera_data *cam,
 	/* Copy cam->curbuff in case it changes while we're processing */
 	frame = cam->curbuff;
 	if (noblock && frame->status != FRAME_READY) {
-		mutex_unlock(&cam->busy_lock);
 		return -EAGAIN;
 	}
 
-	if(frame->status != FRAME_READY) {
-		mutex_unlock(&cam->busy_lock);
+	if (frame->status != FRAME_READY) {
+		mutex_unlock(&cam->v4l2_lock);
 		wait_event_interruptible(cam->wq_stream,
 			       !cam->present ||
 			       (frame = cam->curbuff)->status == FRAME_READY);
+		mutex_lock(&cam->v4l2_lock);
 		if (signal_pending(current))
 			return -ERESTARTSYS;
-		/* make this _really_ smp and multithread-safe */
-		if (mutex_lock_interruptible(&cam->busy_lock)) {
-			return -ERESTARTSYS;
-		}
-		if(!cam->present) {
-			mutex_unlock(&cam->busy_lock);
+		if (!cam->present)
 			return 0;
-		}
 	}
 
 	/* copy data to user space */
-	if (frame->length > count) {
-		mutex_unlock(&cam->busy_lock);
+	if (frame->length > count)
 		return -EFAULT;
-	}
-	if (copy_to_user(buf, frame->data, frame->length)) {
-		mutex_unlock(&cam->busy_lock);
+	if (copy_to_user(buf, frame->data, frame->length))
 		return -EFAULT;
-	}
 
 	count = frame->length;
 
 	frame->status = FRAME_EMPTY;
 
-	mutex_unlock(&cam->busy_lock);
 	return count;
 }
 
@@ -2447,17 +2431,13 @@ unsigned int cpia2_poll(struct camera_data *cam, struct file *filp,
 {
 	unsigned int status=0;
 
-	if(!cam) {
+	if (!cam) {
 		ERR("%s: Internal error, camera_data not found!\n",__func__);
 		return POLLERR;
 	}
 
-	mutex_lock(&cam->busy_lock);
-
-	if(!cam->present) {
-		mutex_unlock(&cam->busy_lock);
+	if (!cam->present)
 		return POLLHUP;
-	}
 
 	if(!cam->streaming) {
 		/* Start streaming */
@@ -2465,16 +2445,13 @@ unsigned int cpia2_poll(struct camera_data *cam, struct file *filp,
 				       cam->params.camera_state.stream_mode);
 	}
 
-	mutex_unlock(&cam->busy_lock);
 	poll_wait(filp, &cam->wq_stream, wait);
-	mutex_lock(&cam->busy_lock);
 
 	if(!cam->present)
 		status = POLLHUP;
 	else if(cam->curbuff->status == FRAME_READY)
 		status = POLLIN | POLLRDNORM;
 
-	mutex_unlock(&cam->busy_lock);
 	return status;
 }
 
@@ -2496,29 +2473,19 @@ int cpia2_remap_buffer(struct camera_data *cam, struct vm_area_struct *vma)
 
 	DBG("mmap offset:%ld size:%ld\n", start_offset, size);
 
-	/* make this _really_ smp-safe */
-	if (mutex_lock_interruptible(&cam->busy_lock))
-		return -ERESTARTSYS;
-
-	if (!cam->present) {
-		mutex_unlock(&cam->busy_lock);
+	if (!cam->present)
 		return -ENODEV;
-	}
 
 	if (size > cam->frame_size*cam->num_frames  ||
 	    (start_offset % cam->frame_size) != 0 ||
-	    (start_offset+size > cam->frame_size*cam->num_frames)) {
-		mutex_unlock(&cam->busy_lock);
+	    (start_offset+size > cam->frame_size*cam->num_frames))
 		return -EINVAL;
-	}
 
 	pos = ((unsigned long) (cam->frame_buffer)) + start_offset;
 	while (size > 0) {
 		page = kvirt_to_pa(pos);
-		if (remap_pfn_range(vma, start, page >> PAGE_SHIFT, PAGE_SIZE, PAGE_SHARED)) {
-			mutex_unlock(&cam->busy_lock);
+		if (remap_pfn_range(vma, start, page >> PAGE_SHIFT, PAGE_SIZE, PAGE_SHARED))
 			return -EAGAIN;
-		}
 		start += PAGE_SIZE;
 		pos += PAGE_SIZE;
 		if (size > PAGE_SIZE)
@@ -2528,7 +2495,5 @@ int cpia2_remap_buffer(struct camera_data *cam, struct vm_area_struct *vma)
 	}
 
 	cam->mmapped = true;
-	mutex_unlock(&cam->busy_lock);
 	return 0;
 }
-