1 files changed, 28 insertions, 11 deletions

diff --git a/Documentation/video4linux/v4l2-pci-skeleton.c b/Documentation/video4linux/v4l2-pci-skeleton.c
index 3a1c0d2dafce..80251dc2c6cf 100644
--- a/Documentation/video4linux/v4l2-pci-skeleton.c
+++ b/Documentation/video4linux/v4l2-pci-skeleton.c
@@ -77,7 +77,8 @@ struct skeleton {
 
         spinlock_t qlock;
         struct list_head buf_list;
-        unsigned int sequence;
+        unsigned field;
+        unsigned sequence;
 };
 
 struct skel_buffer {
@@ -124,7 +125,7 @@ static const struct v4l2_dv_timings_cap skel_timings_cap = {
  * Interrupt handler: typically interrupts happen after a new frame has been
  * captured. It is the job of the handler to remove the new frame from the
  * internal list and give it back to the vb2 framework, updating the sequence
- * counter and timestamp at the same time.
+ * counter, field and timestamp at the same time.
  */
 static irqreturn_t skeleton_irq(int irq, void *dev_id)
 {
@@ -139,8 +140,15 @@ static irqreturn_t skeleton_irq(int irq, void *dev_id)
                 spin_lock(&skel->qlock);
                 list_del(&new_buf->list);
                 spin_unlock(&skel->qlock);
-                new_buf->vb.v4l2_buf.sequence = skel->sequence++;
                 v4l2_get_timestamp(&new_buf->vb.v4l2_buf.timestamp);
+                new_buf->vb.v4l2_buf.sequence = skel->sequence++;
+                new_buf->vb.v4l2_buf.field = skel->field;
+                if (skel->format.field == V4L2_FIELD_ALTERNATE) {
+                        if (skel->field == V4L2_FIELD_BOTTOM)
+                                skel->field = V4L2_FIELD_TOP;
+                        else if (skel->field == V4L2_FIELD_TOP)
+                                skel->field = V4L2_FIELD_BOTTOM;
+                }
                 vb2_buffer_done(&new_buf->vb, VB2_BUF_STATE_DONE);
         }
 #endif
@@ -160,6 +168,17 @@ static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
 {
         struct skeleton *skel = vb2_get_drv_priv(vq);
 
+        skel->field = skel->format.field;
+        if (skel->field == V4L2_FIELD_ALTERNATE) {
+                /*
+                 * You cannot use read() with FIELD_ALTERNATE since the field
+                 * information (TOP/BOTTOM) cannot be passed back to the user.
+                 */
+                if (vb2_fileio_is_active(q))
+                        return -EINVAL;
+                skel->field = V4L2_FIELD_TOP;
+        }
+
         if (vq->num_buffers + *nbuffers < 3)
                 *nbuffers = 3 - vq->num_buffers;
 
@@ -173,10 +192,7 @@ static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *fmt,
 
 /*
  * Prepare the buffer for queueing to the DMA engine: check and set the
- * payload size and fill in the field. Note: if the format's field is
- * V4L2_FIELD_ALTERNATE, then vb->v4l2_buf.field should be set in the
- * interrupt handler since that's usually where you know if the TOP or
- * BOTTOM field has been captured.
+ * payload size.
  */
 static int buffer_prepare(struct vb2_buffer *vb)
 {
@@ -190,7 +206,6 @@ static int buffer_prepare(struct vb2_buffer *vb)
         }
 
         vb2_set_plane_payload(vb, 0, size);
-        vb->v4l2_buf.field = skel->format.field;
         return 0;
 }
 
@@ -319,10 +334,12 @@ static void skeleton_fill_pix_format(struct skeleton *skel,
                 /* HDMI input */
                 pix->width = skel->timings.bt.width;
                 pix->height = skel->timings.bt.height;
-                if (skel->timings.bt.interlaced)
-                        pix->field = V4L2_FIELD_INTERLACED;
-                else
+                if (skel->timings.bt.interlaced) {
+                        pix->field = V4L2_FIELD_ALTERNATE;
+                        pix->height /= 2;
+                } else {
                         pix->field = V4L2_FIELD_NONE;
+                }
                 pix->colorspace = V4L2_COLORSPACE_REC709;
         }