From patchwork Fri Sep 7 13:29:03 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hans Verkuil X-Patchwork-Id: 1422301 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 5F0F23FC33 for ; Fri, 7 Sep 2012 13:30:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758841Ab2IGNac (ORCPT ); Fri, 7 Sep 2012 09:30:32 -0400 Received: from smtp-vbr9.xs4all.nl ([194.109.24.29]:3951 "EHLO smtp-vbr9.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756491Ab2IGN3j (ORCPT ); Fri, 7 Sep 2012 09:29:39 -0400 Received: from alastor.dyndns.org (166.80-203-20.nextgentel.com [80.203.20.166] (may be forged)) (authenticated bits=0) by smtp-vbr9.xs4all.nl (8.13.8/8.13.8) with ESMTP id q87DTZlD094433 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Fri, 7 Sep 2012 15:29:36 +0200 (CEST) (envelope-from hverkuil@xs4all.nl) Received: from tschai.lan (tschai.lan [192.168.1.10]) (Authenticated sender: hans) by alastor.dyndns.org (Postfix) with ESMTPSA id CAE8535C0012; Fri, 7 Sep 2012 15:29:28 +0200 (CEST) From: Hans Verkuil To: linux-media@vger.kernel.org Cc: Laurent Pinchart , Hans Verkuil Subject: [RFCv2 API PATCH 03/28] DocBook: improve STREAMON/OFF documentation. Date: Fri, 7 Sep 2012 15:29:03 +0200 Message-Id: <133a249609e30bd0c77fcc12c01b8899f3ff81d7.1347023744.git.hans.verkuil@cisco.com> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1347024568-32602-1-git-send-email-hverkuil@xs4all.nl> References: <1347024568-32602-1-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 Reviewed-by: Sylwester Nawrocki Acked-by: Laurent Pinchart --- 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