diff options
authorHans Verkuil <>2009-08-07 07:28:16 -0300
committerMauro Carvalho Chehab <>2009-08-13 20:39:12 -0300
commit9bedc7f7fe803c17d26b5fcf5786b50a7cf40def (patch)
parent99362e1ece9f9651af1b849a01d91b9df1e0db2c (diff)
V4L/DVB (12429): v4l2-ioctl: fix G_STD and G_PARM default handlers
The v4l core supplies default handlers for G_STD and G_PARM. However, both default handlers are buggy. This patch fixes the following: 1) If no g_std is supplied and current_norm == 0, then this driver does not support TV video standards (e.g. a radio or webcam driver). Return -EINVAL. This ensures that there is no bogus VIDIOC_G_STD support for such drivers. 2) The default VIDIOC_G_PARM handler used current_norm instead of first checking if the driver supported g_std and calling that to get the norm. It also didn't check if current_norm was 0, since in that case the driver does not support TV standards (or no standard was set at all) and the default handler should return -EINVAL. Note that I am very unhappy with these default handlers: I think they basically behave like some very strange and unexpected side-effect. Signed-off-by: Hans Verkuil <> Signed-off-by: Mauro Carvalho Chehab <>
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index be64a502ea27..f2afc4e08379 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -1081,8 +1081,10 @@ static long __video_do_ioctl(struct file *file,
/* Calls the specific handler */
if (ops->vidioc_g_std)
ret = ops->vidioc_g_std(file, fh, id);
- else
+ else if (vfd->current_norm)
*id = vfd->current_norm;
+ else
+ ret = -EINVAL;
if (!ret)
dbgarg(cmd, "std=0x%08Lx\n", (long long unsigned)*id);
@@ -1553,12 +1555,19 @@ static long __video_do_ioctl(struct file *file,
ret = ops->vidioc_g_parm(file, fh, p);
} else {
+ v4l2_std_id std = vfd->current_norm;
if (p->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
return -EINVAL;
- v4l2_video_std_frame_period(vfd->current_norm,
- &p->parm.capture.timeperframe);
ret = 0;
+ if (ops->vidioc_g_std)
+ ret = ops->vidioc_g_std(file, fh, &std);
+ else if (std == 0)
+ ret = -EINVAL;
+ if (ret == 0)
+ v4l2_video_std_frame_period(std,
+ &p->parm.capture.timeperframe);
dbgarg(cmd, "type=%d\n", p->type);