media: nxp: imx8-isi: Mark all crossbar sink pads as MUST_CONNECT

All the sink pads of the crossbar switch require an active link if
they're part of the pipeline. Mark them with the
MEDIA_PAD_FL_MUST_CONNECT flag to fail pipeline validation if they're
not connected. This allows removing a manual check when translating
streams.

Cc: stable@vger.kernel.org # 6.1
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/platform/nxp/imx8-isi/imx8-isi-crossbar.c

@@ -160,13 +160,6 @@ mxc_isi_crossbar_xlate_streams(struct mxc_isi_crossbar *xbar,
 	}
 
 	pad = media_pad_remote_pad_first(&xbar->pads[sink_pad]);
-	if (!pad) {
-		dev_dbg(xbar->isi->dev,
-			"no pad connected to crossbar input %u\n",
-			sink_pad);
-		return ERR_PTR(-EPIPE);
-	}
-
 	sd = media_entity_to_v4l2_subdev(pad->entity);
 	if (!sd) {
 		dev_dbg(xbar->isi->dev,
@@ -475,7 +468,8 @@ int mxc_isi_crossbar_init(struct mxc_isi_dev *isi)
 	}
 
 	for (i = 0; i < xbar->num_sinks; ++i)
-		xbar->pads[i].flags = MEDIA_PAD_FL_SINK;
+		xbar->pads[i].flags = MEDIA_PAD_FL_SINK
+				    | MEDIA_PAD_FL_MUST_CONNECT;
 	for (i = 0; i < xbar->num_sources; ++i)
 		xbar->pads[i + xbar->num_sinks].flags = MEDIA_PAD_FL_SOURCE;