struct fimc_lite *fimc = video_drvdata(file);
        int ret;
 
+       if (mutex_lock_interruptible(&fimc->lock))
+               return -ERESTARTSYS;
+
        set_bit(ST_FLITE_IN_USE, &fimc->state);
        ret = pm_runtime_get_sync(&fimc->pdev->dev);
        if (ret < 0)
-               return ret;
-
-       if (++fimc->ref_count != 1 || fimc->out_path != FIMC_IO_DMA)
-               return 0;
+               goto done;
 
        ret = v4l2_fh_open(file);
        if (ret < 0)
-               return ret;
+               goto done;
 
-       ret = fimc_pipeline_initialize(&fimc->pipeline, &fimc->vfd->entity,
-                                      true);
-       if (ret < 0) {
-               pm_runtime_put_sync(&fimc->pdev->dev);
-               fimc->ref_count--;
-               v4l2_fh_release(file);
-               clear_bit(ST_FLITE_IN_USE, &fimc->state);
-       }
+       if (++fimc->ref_count == 1 && fimc->out_path == FIMC_IO_DMA) {
+               ret = fimc_pipeline_initialize(&fimc->pipeline,
+                                              &fimc->vfd->entity, true);
+               if (ret < 0) {
+                       pm_runtime_put_sync(&fimc->pdev->dev);
+                       fimc->ref_count--;
+                       v4l2_fh_release(file);
+                       clear_bit(ST_FLITE_IN_USE, &fimc->state);
+               }
 
-       fimc_lite_clear_event_counters(fimc);
+               fimc_lite_clear_event_counters(fimc);
+       }
+done:
+       mutex_unlock(&fimc->lock);
        return ret;
 }
 
 static int fimc_lite_close(struct file *file)
 {
        struct fimc_lite *fimc = video_drvdata(file);
+       int ret;
+
+       if (mutex_lock_interruptible(&fimc->lock))
+               return -ERESTARTSYS;
 
        if (--fimc->ref_count == 0 && fimc->out_path == FIMC_IO_DMA) {
                clear_bit(ST_FLITE_IN_USE, &fimc->state);
        if (fimc->ref_count == 0)
                vb2_queue_release(&fimc->vb_queue);
 
-       return v4l2_fh_release(file);
+       ret = v4l2_fh_release(file);
+
+       mutex_unlock(&fimc->lock);
+       return ret;
 }
 
 static unsigned int fimc_lite_poll(struct file *file,
                                   struct poll_table_struct *wait)
 {
        struct fimc_lite *fimc = video_drvdata(file);
-       return vb2_poll(&fimc->vb_queue, file, wait);
+       int ret;
+
+       if (mutex_lock_interruptible(&fimc->lock))
+               return POLL_ERR;
+
+       ret = vb2_poll(&fimc->vb_queue, file, wait);
+       mutex_unlock(&fimc->lock);
+
+       return ret;
 }
 
 static int fimc_lite_mmap(struct file *file, struct vm_area_struct *vma)
 {
        struct fimc_lite *fimc = video_drvdata(file);
-       return vb2_mmap(&fimc->vb_queue, vma);
+       int ret;
+
+       if (mutex_lock_interruptible(&fimc->lock))
+               return -ERESTARTSYS;
+
+       ret = vb2_mmap(&fimc->vb_queue, vma);
+       mutex_unlock(&fimc->lock);
+
+       return ret;
 }
 
 static const struct v4l2_file_operations fimc_lite_fops = {