[media] cx18: Fix videobuf capture

When we moved to 3.0, we found that the cx18 driver was oopsing on close with:

NULL pointer deref at:

[ 2290.461009] Call Trace:
[ 2290.461009]  [<c046007b>] ? pm_qos_add_request+0xc/0x6e
[ 2290.461009]  [<c082631c>] __mutex_lock_common+0x87/0x125
[ 2290.461009]  [<f8970e92>] ? cx18_queue_flush+0x31/0x87 [cx18]
[ 2290.461009]  [<c0436b85>] ? __might_sleep+0x29/0xe4
[ 2290.461009]  [<c0826515>] __mutex_lock_slowpath+0x25/0x27
[ 2290.461009]  [<c08264b2>] ? mutex_lock+0x2e/0x3b
[ 2290.461009]  [<c08264b2>] mutex_lock+0x2e/0x3b
[ 2290.461009]  [<f88d3137>] videobuf_queue_lock+0x13/0x15 [videobuf_core]
[ 2290.461009]  [<f88d3f86>] __videobuf_free+0xfc/0x112 [videobuf_core]
[ 2290.461009]  [<f89741e6>] cx18_v4l2_close+0x158/0x172 [cx18]
[ 2290.461009]  [<c0507522>] ? cpumask_next+0x1a/0x1d
[ 2290.461009]  [<f88a319d>] v4l2_release+0x35/0x52 [videodev]
[ 2290.461009]  [<c04f5717>] fput+0x100/0x1a5
[ 2290.461009]  [<c04f2e09>] filp_close+0x5c/0x64
[ 2290.461009]  [<c04f2e70>] sys_close+0x5f/0x93
[ 2290.461009]  [<c082cd5f>] sysenter_do_call+0x12/0x28

Some digging showed that a merge at some previous point partially
added broken mmap() support, causing this trace. Remove the broken
code completely.

On top of that, the calculation in place for "buffer full" depended on
UYUV instead of HM12, while our GStreamer code was picking HM12 in
some circumstances.

Finally, the V4L2_CAP_STREAMING capability was never exposed. Patch it
into the YUV encoder node only.
Signed-off-by: Simon Farnsworth <simon.farnsworth@onelan.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/cx18/cx18-driver.h

@@ -409,6 +409,7 @@ struct cx18_stream {
 
 	/* Videobuf for YUV video */
 	u32 pixelformat;
+	u32 vb_bytes_per_frame;
 	struct list_head vb_capture;    /* video capture queue */
 	spinlock_t vb_lock;
 	struct timer_list vb_timeout;
@@ -430,10 +431,6 @@ struct cx18_open_id {
 	u32 open_id;
 	int type;
 	struct cx18 *cx;
-
-	struct videobuf_queue vbuf_q;
-	spinlock_t s_lock; /* Protect vbuf_q */
-	enum v4l2_buf_type vb_type;
 };
 
 static inline struct cx18_open_id *fh2id(struct v4l2_fh *fh)

drivers/media/video/cx18/cx18-fileops.c

@@ -784,8 +784,6 @@ int cx18_v4l2_close(struct file *filp)
 		cx18_release_stream(s);
 	} else {
 		cx18_stop_capture(id, 0);
-		if (id->type == CX18_ENC_STREAM_TYPE_YUV)
-			videobuf_mmap_free(&id->vbuf_q);
 	}
 	kfree(id);
 	mutex_unlock(&cx->serialize_lock);

drivers/media/video/cx18/cx18-ioctl.c

@@ -160,12 +160,7 @@ static int cx18_g_fmt_vid_cap(struct file *file, void *fh,
 	pixfmt->priv = 0;
 	if (id->type == CX18_ENC_STREAM_TYPE_YUV) {
 		pixfmt->pixelformat = s->pixelformat;
-		/* HM12 YUV size is (Y=(h*720) + UV=(h*(720/2)))
-		   UYUV YUV size is (Y=(h*720) + UV=(h*(720))) */
-		if (s->pixelformat == V4L2_PIX_FMT_HM12)
-			pixfmt->sizeimage = pixfmt->height * 720 * 3 / 2;
-		else
-			pixfmt->sizeimage = pixfmt->height * 720 * 2;
+		pixfmt->sizeimage = s->vb_bytes_per_frame;
 		pixfmt->bytesperline = 720;
 	} else {
 		pixfmt->pixelformat = V4L2_PIX_FMT_MPEG;
@@ -296,6 +291,12 @@ static int cx18_s_fmt_vid_cap(struct file *file, void *fh,
 		return -EBUSY;
 
 	s->pixelformat = fmt->fmt.pix.pixelformat;
+	/* HM12 YUV size is (Y=(h*720) + UV=(h*(720/2)))
+	   UYUV YUV size is (Y=(h*720) + UV=(h*(720))) */
+	if (s->pixelformat == V4L2_PIX_FMT_HM12)
+		s->vb_bytes_per_frame = h * 720 * 3 / 2;
+	else
+		s->vb_bytes_per_frame = h * 720 * 2;
 
 	mbus_fmt.width = cx->cxhdl.width = w;
 	mbus_fmt.height = cx->cxhdl.height = h;
@@ -463,13 +464,16 @@ static int cx18_s_register(struct file *file, void *fh,
 static int cx18_querycap(struct file *file, void *fh,
 				struct v4l2_capability *vcap)
 {
-	struct cx18 *cx = fh2id(fh)->cx;
+	struct cx18_open_id *id = fh2id(fh);
+	struct cx18 *cx = id->cx;
 
 	strlcpy(vcap->driver, CX18_DRIVER_NAME, sizeof(vcap->driver));
 	strlcpy(vcap->card, cx->card_name, sizeof(vcap->card));
 	snprintf(vcap->bus_info, sizeof(vcap->bus_info),
 		 "PCI:%s", pci_name(cx->pci_dev));
 	vcap->capabilities = cx->v4l2_cap; 	    /* capabilities */
+	if (id->type == CX18_ENC_STREAM_TYPE_YUV)
+		vcap->capabilities |= V4L2_CAP_STREAMING;
 	return 0;
 }
 

drivers/media/video/cx18/cx18-mailbox.c

@@ -196,7 +196,7 @@ static void cx18_mdl_send_to_videobuf(struct cx18_stream *s,
 	}
 
 	/* If we've filled the buffer as per the callers res then dispatch it */
-	if (vb_buf->bytes_used >= (vb_buf->vb.width * vb_buf->vb.height * 2)) {
+	if (vb_buf->bytes_used >= s->vb_bytes_per_frame) {
 		dispatch = 1;
 		vb_buf->bytes_used = 0;
 	}

drivers/media/video/cx18/cx18-streams.c

@@ -138,6 +138,12 @@ static int cx18_prepare_buffer(struct videobuf_queue *q,
 		buf->tvnorm    = cx->std;
 		s->pixelformat = pixelformat;
 
+		/* HM12 YUV size is (Y=(h*720) + UV=(h*(720/2)))
+		   UYUV YUV size is (Y=(h*720) + UV=(h*(720))) */
+		if (s->pixelformat == V4L2_PIX_FMT_HM12)
+			s->vb_bytes_per_frame = height * 720 * 3 / 2;
+		else
+			s->vb_bytes_per_frame = height * 720 * 2;
 		cx18_dma_free(q, s, buf);
 	}
 
@@ -154,6 +160,12 @@ static int cx18_prepare_buffer(struct videobuf_queue *q,
 		buf->tvnorm    = cx->std;
 		s->pixelformat = pixelformat;
 
+		/* HM12 YUV size is (Y=(h*720) + UV=(h*(720/2)))
+		   UYUV YUV size is (Y=(h*720) + UV=(h*(720))) */
+		if (s->pixelformat == V4L2_PIX_FMT_HM12)
+			s->vb_bytes_per_frame = height * 720 * 3 / 2;
+		else
+			s->vb_bytes_per_frame = height * 720 * 2;
 		rc = videobuf_iolock(q, &buf->vb, NULL);
 		if (rc != 0)
 			goto fail;
@@ -287,6 +299,7 @@ static void cx18_stream_init(struct cx18 *cx, int type)
 
 		/* Assume the previous pixel default */
 		s->pixelformat = V4L2_PIX_FMT_HM12;
+		s->vb_bytes_per_frame = cx->cxhdl.height * 720 * 3 / 2;
 	}
 }