V4L/DVB (5569): Fix: v4l1_compat should be called only if V4L1_COMPAT

Added also some explanations about V4L1 handling

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 13 insertions, 1 deletions

diff --git a/drivers/media/video/videodev.c b/drivers/media/video/videodev.c
index f45c625a92f4..db4bee842745 100644
--- a/drivers/media/video/videodev.c
+++ b/drivers/media/video/videodev.c
@@ -438,6 +438,12 @@ static int __video_do_ioctl(struct inode *inode, struct file *file,
         }
 
 #ifdef CONFIG_VIDEO_V4L1_COMPAT
+        /***********************************************************
+         Handles calls to the obsoleted V4L1 API
+         Due to the nature of VIDIOCGMBUF, each driver that supports
+         V4L1 should implement its own handler for this ioctl.
+         ***********************************************************/
+
         /* --- streaming capture ------------------------------------- */
         if (cmd == VIDIOCGMBUF) {
                 struct video_mbuf *p=arg;
@@ -453,11 +459,17 @@ static int __video_do_ioctl(struct inode *inode, struct file *file,
                                                 (unsigned long)p->offsets);
                 return ret;
         }
-#endif
 
+        /********************************************************
+         All other V4L1 calls are handled by v4l1_compat module.
+         Those calls will be translated into V4L2 calls, and
+         __video_do_ioctl will be called again, with one or more
+         V4L2 ioctls.
+         ********************************************************/
         if (_IOC_TYPE(cmd)=='v')
                 return v4l_compat_translate_ioctl(inode,file,cmd,arg,
                                                 __video_do_ioctl);
+#endif
 
         switch(cmd) {
         /* --- capabilities ------------------------------------------ */