V4L/DVB (6096): ivtv: fix V4L2_ENC_CMD_STOP_AT_GOP_END support

Support for V4L2_ENC_CMD_STOP_AT_GOP_END was broken. While the driver
correctly waited for the card to capture until the GOP was complete,
afterwards the driver buffers were just flushed instead of waiting
for the application to read all the pending data.
Signed-off-by: NHans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: NMauro Carvalho Chehab <mchehab@infradead.org>

drivers/media/video/ivtv/ivtv-fileops.c

@@ -258,19 +258,19 @@ static struct ivtv_buffer *ivtv_get_buffer(struct ivtv_stream *s, int non_block,
 			}
 			return buf;
 		}
-		/* return if file was opened with O_NONBLOCK */
-		if (non_block) {
-			*err = -EAGAIN;
-			return NULL;
-		}
 
 		/* return if end of stream */
 		if (s->type != IVTV_DEC_STREAM_TYPE_VBI && !test_bit(IVTV_F_S_STREAMING, &s->s_flags)) {
-			clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
 			IVTV_DEBUG_INFO("EOS %s\n", s->name);
 			return NULL;
 		}
 
+		/* return if file was opened with O_NONBLOCK */
+		if (non_block) {
+			*err = -EAGAIN;
+			return NULL;
+		}
+
 		/* wait for more data to arrive */
 		prepare_to_wait(&s->waitq, &wait, TASK_INTERRUPTIBLE);
 		/* New buffers might have become available before we were added to the waitqueue */
@@ -378,10 +378,20 @@ static ssize_t ivtv_read(struct ivtv_stream *s, char __user *ubuf, size_t tot_co
 		int rc;
 
 		buf = ivtv_get_buffer(s, non_block, &rc);
-		if (buf == NULL && rc == -EAGAIN && tot_written)
-			break;
-		if (buf == NULL)
+		/* if there is no data available... */
+		if (buf == NULL) {
+			/* if we got data, then return that regardless */
+			if (tot_written)
+				break;
+			/* EOS condition */
+			if (rc == 0) {
+				clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
+				clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
+				ivtv_release_stream(s);
+			}
+			/* set errno */
 			return rc;
+		}
 		rc = ivtv_copy_buf_to_user(s, buf, ubuf + tot_written, tot_count - tot_written);
 		if (buf != &itv->vbi.sliced_mpeg_buf) {
 			ivtv_enqueue(s, buf, (buf->readpos == buf->bytesused) ? &s->q_free : &s->q_io);
@@ -738,10 +748,11 @@ void ivtv_stop_capture(struct ivtv_open_id *id, int gop_end)
 			ivtv_stop_v4l2_encode_stream(s, gop_end);
 		}
 	}
-	clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
-	clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
-
-	ivtv_release_stream(s);
+	if (!gop_end) {
+		clear_bit(IVTV_F_S_APPL_IO, &s->s_flags);
+		clear_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
+		ivtv_release_stream(s);
+	}
 }
 
 static void ivtv_stop_decoding(struct ivtv_open_id *id, int flags, u64 pts)

drivers/media/video/ivtv/ivtv-streams.c

@@ -719,7 +719,6 @@ int ivtv_stop_v4l2_encode_stream(struct ivtv_stream *s, int gop_end)
 	struct ivtv *itv = s->itv;
 	DECLARE_WAITQUEUE(wait, current);
 	int cap_type;
-	unsigned long then;
 	int stopmode;
 
 	if (s->v4l2dev == NULL)
@@ -762,14 +761,12 @@ int ivtv_stop_v4l2_encode_stream(struct ivtv_stream *s, int gop_end)
 	/* when: 0 =  end of GOP  1 = NOW!, type: 0 = mpeg, subtype: 3 = video+audio */
 	ivtv_vapi(itv, CX2341X_ENC_STOP_CAPTURE, 3, stopmode, cap_type, s->subtype);
 
-	then = jiffies;
-
 	if (!test_bit(IVTV_F_S_PASSTHROUGH, &s->s_flags)) {
 		if (s->type == IVTV_ENC_STREAM_TYPE_MPG && gop_end) {
 			/* only run these if we're shutting down the last cap */
 			unsigned long duration;
+			unsigned long then = jiffies;
 
-			then = jiffies;
 			add_wait_queue(&itv->eos_waitq, &wait);
 
 			set_current_state(TASK_INTERRUPTIBLE);
@@ -797,10 +794,9 @@ int ivtv_stop_v4l2_encode_stream(struct ivtv_stream *s, int gop_end)
 			}
 			set_current_state(TASK_RUNNING);
 			remove_wait_queue(&itv->eos_waitq, &wait);
+			set_bit(IVTV_F_S_STREAMOFF, &s->s_flags);
 		}
 
-		then = jiffies;
-
 		/* Handle any pending interrupts */
 		ivtv_msleep_timeout(100, 1);
 	}