From 8c42694150c27ea68a8d46996d943918c769d1d0 Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Date: Fri, 18 Jun 2021 14:29:18 +0200 Subject: [PATCH] media: docs: Document the behaviour of uvcvideo driver The uvc driver relies on the camera firmware to keep the control states and therefore is not capable of changing an inactive control. Allow returning -EACCES in those cases. Signed-off-by: Ricardo Ribalda Signed-off-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst | 3 +++ Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst | 3 +++ 2 files changed, 6 insertions(+) diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst index 80e8c63d530f8..fd09677f64f8d 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst @@ -95,3 +95,6 @@ EBUSY EACCES Attempt to set a read-only control or to get a write-only control. + + Or if there is an attempt to set an inactive control and the driver is + not capable of caching the new value until the control is active again. diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst index 2d6bc8d943806..fdde0ae6d5214 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst @@ -470,3 +470,6 @@ EACCES Or the ``which`` field was set to ``V4L2_CTRL_WHICH_REQUEST_VAL`` but the device does not support requests. + + Or if there is an attempt to set an inactive control and the driver is + not capable of caching the new value until the control is active again. -- 2.30.2