From patchwork Fri Oct 31 14:48:28 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Farnsworth X-Patchwork-Id: 5205381 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 6B0479F30B for ; Fri, 31 Oct 2014 15:12:29 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 3D207201B4 for ; Fri, 31 Oct 2014 15:12:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C793920176 for ; Fri, 31 Oct 2014 15:12:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933279AbaJaPMY (ORCPT ); Fri, 31 Oct 2014 11:12:24 -0400 Received: from claranet-outbound-smtp05.uk.clara.net ([195.8.89.38]:55380 "EHLO claranet-outbound-smtp05.uk.clara.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933066AbaJaPMX (ORCPT ); Fri, 31 Oct 2014 11:12:23 -0400 X-Greylist: delayed 1423 seconds by postgrey-1.27 at vger.kernel.org; Fri, 31 Oct 2014 11:12:23 EDT Received: from 110.100.155.90.in-addr.arpa ([90.155.100.110]:26620 helo=f19simon.office.onelan.co.uk) by relay15.mail.eu.clara.net (relay.clara.net [81.171.239.35]:1025) with esmtpa (authdaemon_plain:simon.farnsworth@onelan.co.uk) id 1XkDVC-0002ks-Hj (return-path ); Fri, 31 Oct 2014 14:48:34 +0000 From: Simon Farnsworth To: linux-media@vger.kernel.org Cc: hverkuil@xs4all.nl, Simon Farnsworth Subject: [PATCH] DocBook media: Clarify V4L2_FIELD_ANY for drivers Date: Fri, 31 Oct 2014 14:48:28 +0000 Message-Id: <1414766908-24894-1-git-send-email-simon.farnsworth@onelan.co.uk> X-Mailer: git-send-email 1.9.3 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Documentation for enum v4l2_field did not make it clear that V4L2_FIELD_ANY is only acceptable as input to the kernel, not as a response from the driver. Make it clear, to stop userspace developers like me assuming it can be returned by the driver. Signed-off-by: Simon Farnsworth --- Documentation/DocBook/media/v4l/io.xml | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index e5e8325..8918bb2 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -1422,7 +1422,10 @@ one of the V4L2_FIELD_NONE, V4L2_FIELD_BOTTOM, or V4L2_FIELD_INTERLACED formats is acceptable. Drivers choose depending on hardware capabilities or e. g. the -requested image size, and return the actual field order. &v4l2-buffer; +requested image size, and return the actual field order. If multiple +field orders are possible the driver must choose one of the possible +field orders during &VIDIOC-S-FMT; or &VIDIOC-TRY-FMT; and must not +return V4L2_FIELD_ANY. &v4l2-buffer; field can never be V4L2_FIELD_ANY.