[media] hdpvr: fix interrupted recording

This is a reworking of a patch originally submitted by Ryley Angus,
modified by Hans Verkuil and then seemingly forgotten before changes
suggested by Keith Pyle here:

http://www.mail-archive.com/linux-media@vger.kernel.org/msg75163.html

were made and tested.

I have implemented the suggested changes and have been testing for the
last 2 months. I am no longer experiencing lockups while recording
(with blue light on, requiring power cycling) which had been a long
standing problem with the HD-PVR. I have not noticed any other problems
since applying the patch.

Signed-off-by: Jonathan Sims <jonathan.625266@earthlink.net>
Reported-by: Ryley Angus <ryleyjangus@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/usb/hdpvr/hdpvr-video.c

@@ -449,6 +449,7 @@ static ssize_t hdpvr_read(struct file *file, char __user *buffer, size_t count,
 
 		if (buf->status != BUFSTAT_READY &&
 		    dev->status != STATUS_DISCONNECTED) {
+			int err;
 			/* return nonblocking */
 			if (file->f_flags & O_NONBLOCK) {
 				if (!ret)
@@ -456,9 +457,24 @@ static ssize_t hdpvr_read(struct file *file, char __user *buffer, size_t count,
 				goto err;
 			}
 
-			if (wait_event_interruptible(dev->wait_data,
-					      buf->status == BUFSTAT_READY))
-				return -ERESTARTSYS;
+			err = wait_event_interruptible_timeout(dev->wait_data,
+				buf->status == BUFSTAT_READY,
+				msecs_to_jiffies(1000));
+			if (err < 0) {
+				ret = err;
+				goto err;
+			}
+			if (!err) {
+				v4l2_dbg(MSG_INFO, hdpvr_debug, &dev->v4l2_dev,
+					"timeout: restart streaming\n");
+				hdpvr_stop_streaming(dev);
+				msecs_to_jiffies(4000);
+				err = hdpvr_start_streaming(dev);
+				if (err) {
+					ret = err;
+					goto err;
+				}
+			}
 		}
 
 		if (buf->status != BUFSTAT_READY)