diff -r 87aa6048e718 linux/drivers/media/video/pwc/pwc-v4l.c
--- a/linux/drivers/media/video/pwc/pwc-v4l.c	Wed Jul 02 08:59:38 2008 -0300
+++ b/linux/drivers/media/video/pwc/pwc-v4l.c	Sat Jul 05 14:14:03 2008 +0100
@@ -1134,6 +1134,13 @@
 				     frameq is safe now.
 			 */
 			add_wait_queue(&pdev->frameq, &wait);
+
+			if ((pdev->full_frames == NULL) && (file->f_flags & O_NONBLOCK)) {
+				remove_wait_queue(&pdev->frameq, &wait);
+				set_current_state(TASK_RUNNING);
+				return -EAGAIN;
+			}
+
 			while (pdev->full_frames == NULL) {
 				if (pdev->error_status) {
 					remove_wait_queue(&pdev->frameq, &wait);