V4L/DVB (6049): ivtv: fix VBI reinsertion decoding

- Invalid VBI packets should result in an empty VBI frame, not
  in an zero-sized frame that causes the reader to incorrectly
  return a 0 (EOF) value.
- PIO completion should not reset the sg_pending_size field.
- The DMA offset detection code should be ignored for PIO transfers:
  it somehow messes up the data on the card and is not needed anyway
  for PIO.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

2 files changed, 4 insertions, 5 deletions

diff --git a/drivers/media/video/ivtv/ivtv-irq.c b/drivers/media/video/ivtv/ivtv-irq.c
index 9695e5356163..7272f1a71dd9 100644
--- a/drivers/media/video/ivtv/ivtv-irq.c
+++ b/drivers/media/video/ivtv/ivtv-irq.c
@@ -165,7 +165,7 @@ static int stream_enc_dma_append(struct ivtv_stream *s, u32 data[CX2341X_MBOX_MA
         }
 
         /* if this is the start of the DMA then fill in the magic cookie */
-        if (s->sg_pending_size == 0) {
+        if (s->sg_pending_size == 0 && ivtv_use_dma(s)) {
                 if (itv->has_cx23415 && (s->type == IVTV_ENC_STREAM_TYPE_PCM ||
                     s->type == IVTV_DEC_STREAM_TYPE_VBI)) {
                         s->pending_backup = read_dec(offset - IVTV_DECODER_OFFSET);
@@ -252,7 +252,7 @@ static void dma_post(struct ivtv_stream *s)
                 /* Sync Buffer */
                 ivtv_buf_sync_for_cpu(s, buf);
 
-                if (x == 0) {
+                if (x == 0 && ivtv_use_dma(s)) {
                         offset = s->dma_last_offset;
                         if (u32buf[offset / 4] != DMA_MAGIC_COOKIE)
                         {
@@ -591,7 +591,6 @@ static void ivtv_irq_enc_pio_complete(struct ivtv *itv)
         }
         s = &itv->streams[itv->cur_pio_stream];
         IVTV_DEBUG_HI_IRQ("ENC PIO COMPLETE %s\n", s->name);
-        s->sg_pending_size = 0;
         clear_bit(IVTV_F_I_PIO, &itv->i_flags);
         itv->cur_pio_stream = -1;
         dma_post(s);
diff --git a/drivers/media/video/ivtv/ivtv-vbi.c b/drivers/media/video/ivtv/ivtv-vbi.c
index a7282a91bd97..a58c833c2b04 100644
--- a/drivers/media/video/ivtv/ivtv-vbi.c
+++ b/drivers/media/video/ivtv/ivtv-vbi.c
@@ -163,8 +163,8 @@ static int ivtv_convert_ivtv_vbi(struct ivtv *itv, u8 *p)
                 linemask[1] = 0xf;
                 p += 4;
         } else {
-                /* unknown VBI data stream */
-                return 0;
+                /* unknown VBI data, convert to empty VBI frame */
+                linemask[0] = linemask[1] = 0;
         }
         for (i = 0; i < 36; i++) {
                 int err = 0;