media: v4l: vsp1: Fix header display list status check in continuous mode

To allow dual pipelines utilising two WPF entities when available, the
VSP was updated to support header-mode display list in continuous
pipelines.

A small bug in the status check of the command register causes the
second pipeline to be directly afflicted by the running of the first;
appearing as a perceived performance issue with stuttering display.

Fix the vsp1_dl_list_hw_update_pending() call to ensure that the read
comparison corresponds to the correct pipeline.

Fixes: eaf4bfad6ad8 ("v4l: vsp1: Add support for header display lists in continuous mode")

Cc: "Stable v4.14+" <stable@vger.kernel.org>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/vsp1/vsp1_dl.c

@@ -509,7 +509,8 @@ static bool vsp1_dl_list_hw_update_pending(struct vsp1_dl_manager *dlm)
 		return !!(vsp1_read(vsp1, VI6_DL_BODY_SIZE)
 			  & VI6_DL_BODY_SIZE_UPD);
 	else
-		return !!(vsp1_read(vsp1, VI6_CMD(dlm->index) & VI6_CMD_UPDHDR));
+		return !!(vsp1_read(vsp1, VI6_CMD(dlm->index))
+			  & VI6_CMD_UPDHDR);
 }
 
 static void vsp1_dl_list_hw_enqueue(struct vsp1_dl_list *dl)