From 5f26f2501b81190b60a0b72d611668fb6a59dd24 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 11 Apr 2014 05:02:29 -0300 Subject: [PATCH] [media] v4l2-pci-skeleton.c: fix alternate field handling For interlaced HDTV timings the correct field setting is FIELD_ALTERNATE, not INTERLACED. Update this template driver accordingly: - add check for the invalid combination of read() and FIELD_ALTERNATE. - in the interrupt handler set v4l2_buffer field to alternating TOP and BOTTOM. Signed-off-by: Hans Verkuil Acked-by: Sakari Ailus Signed-off-by: Mauro Carvalho Chehab --- Documentation/video4linux/v4l2-pci-skeleton.c | 39 +++++++++++++------ 1 file 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; } -- 2.20.1