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 <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c
index be64a50..f2afc4e 100644
--- a/drivers/media/video/v4l2-ioctl.c
+++ b/drivers/media/video/v4l2-ioctl.c
@@ -1081,8 +1081,10 @@
/* 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 @@
break;
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);