[PATCHv2 04/15] v4l2-subdev: without controls return -ENOTTY

[Hans Verkuil]

If the subdev did not define any controls, then return -ENOTTY if
userspace attempts to call these ioctls.

The control framework functions will return -EINVAL, not -ENOTTY if
vfh->ctrl_handler is NULL.

Several of these framework functions are also called directly from
drivers, so I don't want to change the error code there.

Found with vimc and v4l2-compliance.

Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
---
 drivers/media/v4l2-core/v4l2-subdev.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/drivers/media/v4l2-core/v4l2-subdev.c 
b/drivers/media/v4l2-core/v4l2-subdev.c
index 43fefa73e0a3..be7a19272614 100644
--- a/drivers/media/v4l2-core/v4l2-subdev.c
+++ b/drivers/media/v4l2-core/v4l2-subdev.c
@@ -187,27 +187,43 @@ static long subdev_do_ioctl(struct file *file, unsigned 
int cmd, void *arg)
 
        switch (cmd) {
        case VIDIOC_QUERYCTRL:
+               if (!vfh->ctrl_handler)
+                       return -ENOTTY;
                return v4l2_queryctrl(vfh->ctrl_handler, arg);
 
        case VIDIOC_QUERY_EXT_CTRL:
+               if (!vfh->ctrl_handler)
+                       return -ENOTTY;
                return v4l2_query_ext_ctrl(vfh->ctrl_handler, arg);
 
        case VIDIOC_QUERYMENU:
+               if (!vfh->ctrl_handler)
+                       return -ENOTTY;
                return v4l2_querymenu(vfh->ctrl_handler, arg);
 
        case VIDIOC_G_CTRL:
+               if (!vfh->ctrl_handler)
+                       return -ENOTTY;
                return v4l2_g_ctrl(vfh->ctrl_handler, arg);
 
        case VIDIOC_S_CTRL:
+               if (!vfh->ctrl_handler)
+                       return -ENOTTY;
                return v4l2_s_ctrl(vfh, vfh->ctrl_handler, arg);
 
        case VIDIOC_G_EXT_CTRLS:
+               if (!vfh->ctrl_handler)
+                       return -ENOTTY;
                return v4l2_g_ext_ctrls(vfh->ctrl_handler, arg);
 
        case VIDIOC_S_EXT_CTRLS:
+               if (!vfh->ctrl_handler)
+                       return -ENOTTY;
                return v4l2_s_ext_ctrls(vfh, vfh->ctrl_handler, arg);
 
        case VIDIOC_TRY_EXT_CTRLS:
+               if (!vfh->ctrl_handler)
+                       return -ENOTTY;
                return v4l2_try_ext_ctrls(vfh->ctrl_handler, arg);
 
        case VIDIOC_DQEVENT:
-- 
2.15.1