From: Hans Verkuil <hansverk@xxxxxxxxx>
For now (this might be relaxed in the future) we do not allow getting
controls from a request that isn't completed. In that case we return
-EACCES. Update the documentation accordingly.
Signed-off-by: Hans Verkuil <hansverk@xxxxxxxxx>
---
.../media/uapi/v4l/vidioc-g-ext-ctrls.rst | 18 +++++++++---------
drivers/media/v4l2-core/v4l2-ctrls.c | 5 ++---
2 files changed, 11 insertions(+), 12 deletions(-)
diff --git a/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst b/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
index 9c56a9b6e98a..ad8908ce3095 100644
--- a/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
+++ b/Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst
@@ -107,13 +107,12 @@ then ``EINVAL`` will be returned.
An attempt to call :ref:`VIDIOC_S_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>` for a
request that has already been queued will result in an ``EBUSY`` error.
-If ``request_fd`` is specified and ``which`` is set to ``V4L2_CTRL_WHICH_REQUEST_VAL``
-during a call to :ref:`VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`, then the
-returned values will be the values currently set for the request (or the
-hardware value if none is set) if the request has not yet been queued, or the
-values of the controls at the time of request completion if it has already
-completed. Attempting to get controls while the request has been queued but
-not yet completed will result in an ``EBUSY`` error.
+If ``request_fd`` is specified and ``which`` is set to
+``V4L2_CTRL_WHICH_REQUEST_VAL`` during a call to
+:ref:`VIDIOC_G_EXT_CTRLS <VIDIOC_G_EXT_CTRLS>`, then it will return the
+values of the controls at the time of request completion.
+If the request is not yet completed, then this will result in an
+``EACCES`` error.
The driver will only set/get these controls if all control values are
correct. This prevents the situation where only some of the controls
@@ -405,8 +404,9 @@ ENOSPC
and this error code is returned.
EACCES
- Attempt to try or set a read-only control or to get a write-only
- control.
+ Attempt to try or set a read-only control, or to get a write-only
+ control, or to get a control from a request that has not yet been
+ completed.
EPERM
The ``which`` field was set to ``V4L2_CTRL_WHICH_REQUEST_VAL`` but the
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index a197b60183f5..ccaf3068de6d 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -3301,10 +3301,9 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct media_device *mdev,
if (IS_ERR(req))
return PTR_ERR(req);
- if (req->state != MEDIA_REQUEST_STATE_IDLE &&
- req->state != MEDIA_REQUEST_STATE_COMPLETE) {
+ if (req->state != MEDIA_REQUEST_STATE_COMPLETE) {
media_request_put(req);
- return -EBUSY;
+ return -EACCES;
}
obj = v4l2_ctrls_find_req_obj(hdl, req, false);
--
2.18.0
