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>

diff --git a/drivers/media/video/videodev.c b/drivers/media/video/videodev.c
index f45c625a92f453a8d5a47973e895bdcab841f78b..db4bee8427458d7f533bc42723ab816697cdfcfa 100644 (file)
--- 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 ------------------------------------------ */