V4L/DVB (8648): ivtv: improve CC support

- change the work-queue to a single threaded high prio workqueue
- use DMA instead of PIO for the sliced VBI data.
- remove some incorrect tests
- increase the internal VBI capture queue size for sliced VBI packets
- ignore duplicate VBI lines

With these changes it should finally be possible to get reliable closed
captions.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

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

@@ -688,7 +688,7 @@ static int __devinit ivtv_init_struct1(struct ivtv *itv)
 	spin_lock_init(&itv->lock);
 	spin_lock_init(&itv->dma_reg_lock);
 
-	itv->irq_work_queues = create_workqueue(itv->name);
+	itv->irq_work_queues = create_singlethread_workqueue(itv->name);
 	if (itv->irq_work_queues == NULL) {
 		IVTV_ERR("Could not create ivtv workqueue\n");
 		return -1;

drivers/media/video/ivtv/ivtv-driver.h

@@ -251,6 +251,7 @@ struct ivtv_mailbox_data {
 #define IVTV_F_I_DEC_PAUSED	   20 	/* the decoder is paused */
 #define IVTV_F_I_INITED		   21 	/* set after first open */
 #define IVTV_F_I_FAILED		   22 	/* set if first open failed */
+#define IVTV_F_I_WORK_INITED       23	/* worker thread was initialized */
 
 /* Event notifications */
 #define IVTV_F_I_EV_DEC_STOPPED	   28	/* decoder stopped event */

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

@@ -76,6 +76,13 @@ void ivtv_irq_work_handler(struct work_struct *work)
 
 	DEFINE_WAIT(wait);
 
+	if (test_and_clear_bit(IVTV_F_I_WORK_INITED, &itv->i_flags)) {
+		struct sched_param param = { .sched_priority = 99 };
+
+		/* This thread must use the FIFO scheduler as it
+		   is realtime sensitive. */
+		sched_setscheduler(current, SCHED_FIFO, &param);
+	}
 	if (test_and_clear_bit(IVTV_F_I_WORK_HANDLER_PIO, &itv->i_flags))
 		ivtv_pio_work_handler(itv);
 
@@ -678,34 +685,14 @@ static void ivtv_irq_enc_start_cap(struct ivtv *itv)
 
 static void ivtv_irq_enc_vbi_cap(struct ivtv *itv)
 {
-	struct ivtv_stream *s_mpg = &itv->streams[IVTV_ENC_STREAM_TYPE_MPG];
 	u32 data[CX2341X_MBOX_MAX_DATA];
 	struct ivtv_stream *s;
 
 	IVTV_DEBUG_HI_IRQ("ENC START VBI CAP\n");
 	s = &itv->streams[IVTV_ENC_STREAM_TYPE_VBI];
 
-	/* If more than two VBI buffers are pending, then
-	   clear the old ones and start with this new one.
-	   This can happen during transition stages when MPEG capturing is
-	   started, but the first interrupts haven't arrived yet. During
-	   that period VBI requests can accumulate without being able to
-	   DMA the data. Since at most four VBI DMA buffers are available,
-	   we just drop the old requests when there are already three
-	   requests queued. */
-	if (s->sg_pending_size > 2) {
-		struct ivtv_buffer *buf;
-		list_for_each_entry(buf, &s->q_predma.list, list)
-			ivtv_buf_sync_for_cpu(s, buf);
-		ivtv_queue_move(s, &s->q_predma, NULL, &s->q_free, 0);
-		s->sg_pending_size = 0;
-	}
-	/* if we can append the data, and the MPEG stream isn't capturing,
-	   then start a DMA request for just the VBI data. */
-	if (!stream_enc_dma_append(s, data) &&
-			!test_bit(IVTV_F_S_STREAMING, &s_mpg->s_flags)) {
+	if (!stream_enc_dma_append(s, data))
 		set_bit(ivtv_use_pio(s) ? IVTV_F_S_PIO_PENDING : IVTV_F_S_DMA_PENDING, &s->s_flags);
-	}
 }
 
 static void ivtv_irq_dec_vbi_reinsert(struct ivtv *itv)

drivers/media/video/ivtv/ivtv-queue.h

@@ -23,7 +23,7 @@
 #define IVTV_QUEUE_H
 
 #define IVTV_DMA_UNMAPPED	((u32) -1)
-#define SLICED_VBI_PIO 1
+#define SLICED_VBI_PIO 0
 
 /* ivtv_buffer utility functions */
 

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

@@ -363,7 +363,7 @@ static void ivtv_vbi_setup(struct ivtv *itv)
 	/* Every X number of frames a VBI interrupt arrives (frames as in 25 or 30 fps) */
 	data[1] = 1;
 	/* The VBI frames are stored in a ringbuffer with this size (with a VBI frame as unit) */
-	data[2] = raw ? 4 : 8;
+	data[2] = raw ? 4 : 4 * (itv->vbi.raw_size / itv->vbi.enc_size);
 	/* The start/stop codes determine which VBI lines end up in the raw VBI data area.
 	   The codes are from table 24 in the saa7115 datasheet. Each raw/sliced/video line
 	   is framed with codes FF0000XX where XX is the SAV/EAV (Start/End of Active Video)

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

@@ -293,6 +293,7 @@ static u32 compress_sliced_buf(struct ivtv *itv, u32 line, u8 *buf, u32 size, u8
 	u32 line_size = itv->vbi.sliced_decoder_line_size;
 	struct v4l2_decode_vbi_line vbi;
 	int i;
+	unsigned lines = 0;
 
 	/* find the first valid line */
 	for (i = 0; i < size; i++, buf++) {
@@ -313,7 +314,8 @@ static u32 compress_sliced_buf(struct ivtv *itv, u32 line, u8 *buf, u32 size, u8
 		}
 		vbi.p = p + 4;
 		itv->video_dec_func(itv, VIDIOC_INT_DECODE_VBI_LINE, &vbi);
-		if (vbi.type) {
+		if (vbi.type && !(lines & (1 << vbi.line))) {
+			lines |= 1 << vbi.line;
 			itv->vbi.sliced_data[line].id = vbi.type;
 			itv->vbi.sliced_data[line].field = vbi.is_second_field;
 			itv->vbi.sliced_data[line].line = vbi.line;