From patchwork Mon Sep 3 13:48:37 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans Verkuil X-Patchwork-Id: 1399811 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 77688402E1 for ; Mon, 3 Sep 2012 13:49:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932121Ab2ICNtN (ORCPT ); Mon, 3 Sep 2012 09:49:13 -0400 Received: from smtp-vbr16.xs4all.nl ([194.109.24.36]:4123 "EHLO smtp-vbr16.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752941Ab2ICNsv (ORCPT ); Mon, 3 Sep 2012 09:48:51 -0400 Received: from alastor.dyndns.org (166.80-203-20.nextgentel.com [80.203.20.166] (may be forged)) (authenticated bits=0) by smtp-vbr16.xs4all.nl (8.13.8/8.13.8) with ESMTP id q83DmnHG039455 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Mon, 3 Sep 2012 15:48:49 +0200 (CEST) (envelope-from hverkuil@xs4all.nl) Received: from durdane.fritz.box (marune.xs4all.nl [80.101.105.217]) (Authenticated sender: hans) by alastor.dyndns.org (Postfix) with ESMTPSA id 8161535E0276; Mon, 3 Sep 2012 15:48:47 +0200 (CEST) From: Hans Verkuil To: linux-media@vger.kernel.org Cc: Hans Verkuil Subject: [RFC PATCH 03/10] DocBook: improve STREAMON/OFF documentation. Date: Mon, 3 Sep 2012 15:48:37 +0200 Message-Id: X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1346680124-15169-1-git-send-email-hverkuil@xs4all.nl> References: <1346680124-15169-1-git-send-email-hverkuil@xs4all.nl> In-Reply-To: References: X-Virus-Scanned: by XS4ALL Virus Scanner Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org From: Hans Verkuil Specify that STREAMON/OFF should return 0 if the stream is already started/stopped. The spec never specified what the correct behavior is. This ambiguity was resolved during the 2012 Media Workshop. Signed-off-by: Hans Verkuil --- Documentation/DocBook/media/v4l/vidioc-streamon.xml | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/Documentation/DocBook/media/v4l/vidioc-streamon.xml b/Documentation/DocBook/media/v4l/vidioc-streamon.xml index 81cca45..716ea15 100644 --- a/Documentation/DocBook/media/v4l/vidioc-streamon.xml +++ b/Documentation/DocBook/media/v4l/vidioc-streamon.xml @@ -74,7 +74,12 @@ not transmitted yet. I/O returns to the same state as after calling stream type. This is the same as &v4l2-requestbuffers; type. - Note applications can be preempted for unknown periods right + If VIDIOC_STREAMON is called when streaming +is already in progress, or if VIDIOC_STREAMOFF is called +when streaming is already stopped, then the ioctl does nothing and 0 is +returned. + + Note that applications can be preempted for unknown periods right before or after the VIDIOC_STREAMON or VIDIOC_STREAMOFF calls, there is no notion of starting or stopping "now". Buffer timestamps can be used to