V4L/DVB (9911): em28xx: vidioc_try_fmt_vid_cap() doesn't need any lock
authorMauro Carvalho Chehab <mchehab@redhat.com>
Tue, 16 Dec 2008 23:36:13 +0000 (20:36 -0300)
committerMauro Carvalho Chehab <mchehab@redhat.com>
Tue, 30 Dec 2008 11:39:14 +0000 (09:39 -0200)
vidioc_try_fmt_vid_cap() just checks if a given resolution is supported.
It doesn't touch on struct em28xx device descriptor. so, there's no need
to lock.

While there, use unlikely() for those values that aren't likely to
occur.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
drivers/media/video/em28xx/em28xx-video.c

index 2d88afe..1681af1 100644 (file)
@@ -730,19 +730,17 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
        /* width must even because of the YUYV format
           height must be even because of interlacing */
        height &= 0xfffe;
-       width &= 0xfffe;
+       width  &= 0xfffe;
 
-       if (height < 32)
+       if (unlikely(height < 32))
                height = 32;
-       if (height > maxh)
+       if (unlikely(height > maxh))
                height = maxh;
-       if (width < 48)
+       if (unlikely(width < 48))
                width = 48;
-       if (width > maxw)
+       if (unlikely(width > maxw))
                width = maxw;
 
-       mutex_lock(&dev->lock);
-
        if (dev->board.is_em2800) {
                /* the em2800 can only scale down to 50% */
                if (height % (maxh / 2))
@@ -772,7 +770,6 @@ static int vidioc_try_fmt_vid_cap(struct file *file, void *priv,
        f->fmt.pix.colorspace = V4L2_COLORSPACE_SMPTE170M;
        f->fmt.pix.field = V4L2_FIELD_INTERLACED;
 
-       mutex_unlock(&dev->lock);
        return 0;
 }