From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:48608 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727787AbeKVEJE (ORCPT ); Wed, 21 Nov 2018 23:09:04 -0500 From: Sakari Ailus To: linux-media@vger.kernel.org Cc: hverkuil@xs4all.nl Subject: [PATCH 1/1] v4l: uAPI doc: Changing frame interval won't change format Date: Wed, 21 Nov 2018 19:33:44 +0200 Message-Id: <20181121173344.4055-1-sakari.ailus@linux.intel.com> Sender: linux-media-owner@vger.kernel.org List-ID: Document that changing the frame interval has no effect on frame size. While this was the assumption in the API, it was not documented as such. Signed-off-by: Sakari Ailus --- Documentation/media/uapi/v4l/vidioc-g-parm.rst | 3 +++ Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst | 3 +++ 2 files changed, 6 insertions(+) diff --git a/Documentation/media/uapi/v4l/vidioc-g-parm.rst b/Documentation/media/uapi/v4l/vidioc-g-parm.rst index e831fa5512f0..c31585a7701b 100644 --- a/Documentation/media/uapi/v4l/vidioc-g-parm.rst +++ b/Documentation/media/uapi/v4l/vidioc-g-parm.rst @@ -42,6 +42,9 @@ side. This is especially useful when using the :ref:`read() ` or :ref:`write() `, which are not augmented by timestamps or sequence counters, and to avoid unnecessary data copying. +Changing the frame interval shall never change the format. Changing the +format, on the other hand, may change the frame interval. + Further these ioctls can be used to determine the number of buffers used internally by a driver in read/write mode. For implications see the section discussing the :ref:`read() ` function. diff --git a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst index 5af0a7179941..f889c20f231c 100644 --- a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst +++ b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst @@ -63,6 +63,9 @@ doesn't match the device capabilities. They must instead modify the interval to match what the hardware can provide. The modified interval should be as close as possible to the original request. +Changing the frame interval shall never change the format. Changing the +format, on the other hand, may change the frame interval. + Sub-devices that support the frame interval ioctls should implement them on a single pad only. Their behaviour when supported on multiple pads of the same sub-device is not defined. -- 2.11.0