Messages in this thread | | | From | Ricardo Ribalda <> | Date | Sat, 27 Mar 2021 13:01:05 +0100 | Subject | Re: [PATCH v9 17/22] media: docs: Document the behaviour of uvcdriver |
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Hi Hans
Thanks for your review!
On Sat, Mar 27, 2021 at 12:19 PM Hans Verkuil <hverkuil-cisco@xs4all.nl> wrote: > > On 26/03/2021 10:58, Ricardo Ribalda wrote: > > 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 -EACESS in those cases. > > -EACCES
This british people that like to have a lot of double consonants :)
I have updated the series at:
https://git.kernel.org/pub/scm/linux/kernel/git/ribalda/linux.git/log/?h=uvc-compliance-v10
Will not post until there is more feedback to avoid spamming the list.
Thanks :)
> > > > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > --- > > Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst | 5 +++++ > > Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst | 5 +++++ > > 2 files changed, 10 insertions(+) > > > > diff --git a/Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst b/Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst > > index 4f1bed53fad5..8c0a203385c2 100644 > > --- a/Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst > > +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ctrl.rst > > @@ -95,3 +95,8 @@ 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 keeping the new value until the control is active again. > > keeping: 'caching' or 'storing' are better words, I think. > > > + This is the case for drivers that do not use the standard control > > + framework and rely purely on the hardware to keep the controls' state. > > I would drop that last sentence. It is not relevant information to the users of > the API. > > > 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 b9c62affbb5a..bb7de7a25241 100644 > > --- a/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > > +++ b/Documentation/userspace-api/media/v4l/vidioc-g-ext-ctrls.rst > > @@ -438,3 +438,8 @@ 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 keeping the new value until the control is active again. > > + This is the case for drivers that do not use the standard control > > + framework and rely purely on the hardware to keep the controls' state. > > Same comments as above. > > > > > Regards, > > Hans
-- Ricardo Ribalda
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