On Thu, Feb 15, 2007 at 04:23:02PM +0100, Geert.Uytterhoeven@sonycom.com wrote:

+	do {
+		try_to_freeze();
+		error = down_interruptible(&ps3fb.sem);
+		if (!error && !atomic_read(&ps3fb.ext_flip))
 			ps3fb_sync(0);	/* single buffer */

this still can deadlock when calling kthread_stop.  You really want
to use wake_up_process to kick this thread or use a workqueue.