From patchwork Tue Jul 5 01:31:11 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 9213395 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7257660467 for ; Tue, 5 Jul 2016 01:32:07 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 620C628800 for ; Tue, 5 Jul 2016 01:32:07 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 56E6128802; Tue, 5 Jul 2016 01:32:07 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E359528800 for ; Tue, 5 Jul 2016 01:32:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932882AbcGEBcE (ORCPT ); Mon, 4 Jul 2016 21:32:04 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:38697 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754230AbcGEBb2 (ORCPT ); Mon, 4 Jul 2016 21:31:28 -0400 Received: from 201.86.133.99.dynamic.adsl.gvt.net.br ([201.86.133.99] helo=smtp.w2.samsung.com) by bombadil.infradead.org with esmtpsa (Exim 4.85_2 #1 (Red Hat Linux)) id 1bKFCx-0001gd-AB; Tue, 05 Jul 2016 01:31:27 +0000 Received: from mchehab by smtp.w2.samsung.com with local (Exim 4.87) (envelope-from ) id 1bKFCp-0001cJ-RQ; Mon, 04 Jul 2016 22:31:19 -0300 From: Mauro Carvalho Chehab To: Linux Media Mailing List Cc: Mauro Carvalho Chehab , Mauro Carvalho Chehab , Jonathan Corbet , Markus Heiser , linux-doc@vger.kernel.org Subject: [PATCH 36/41] Documentation: linux_tv: Use references for read()/write() Date: Mon, 4 Jul 2016 22:31:11 -0300 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: <376f8877e078483e22a906cb0126f8db37bde441.1467670142.git.mchehab@s-opensource.com> References: <376f8877e078483e22a906cb0126f8db37bde441.1467670142.git.mchehab@s-opensource.com> In-Reply-To: <376f8877e078483e22a906cb0126f8db37bde441.1467670142.git.mchehab@s-opensource.com> References: <376f8877e078483e22a906cb0126f8db37bde441.1467670142.git.mchehab@s-opensource.com> Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Use cross-references for read()/write() on a few places where they weren't used. Signed-off-by: Mauro Carvalho Chehab --- Documentation/linux_tv/media/v4l/dev-capture.rst | 4 ++-- Documentation/linux_tv/media/v4l/dev-raw-vbi.rst | 4 ++-- Documentation/linux_tv/media/v4l/func-open.rst | 12 ++++++------ Documentation/linux_tv/media/v4l/open.rst | 3 ++- 4 files changed, 12 insertions(+), 11 deletions(-) diff --git a/Documentation/linux_tv/media/v4l/dev-capture.rst b/Documentation/linux_tv/media/v4l/dev-capture.rst index c927b7834b90..16030a8354fd 100644 --- a/Documentation/linux_tv/media/v4l/dev-capture.rst +++ b/Documentation/linux_tv/media/v4l/dev-capture.rst @@ -97,6 +97,6 @@ requests and always returns default parameters as :ref:`VIDIOC_G_FMT ` -and/or streaming (:ref:`memory mapping ` or +A video capture device may support the ::ref:`read() function ` +and/or streaming (:ref:`memory mapping ` or :ref:`user pointer `) I/O. See :ref:`io` for details. diff --git a/Documentation/linux_tv/media/v4l/dev-raw-vbi.rst b/Documentation/linux_tv/media/v4l/dev-raw-vbi.rst index a26e10e92460..3aa93943fe9f 100644 --- a/Documentation/linux_tv/media/v4l/dev-raw-vbi.rst +++ b/Documentation/linux_tv/media/v4l/dev-raw-vbi.rst @@ -91,8 +91,8 @@ happen for instance when the video and VBI areas to capture would overlap, or when the driver supports multiple opens and another process already requested VBI capturing or output. Anyway, applications must expect other resource allocation points which may return ``EBUSY``, at the -:ref:`VIDIOC_STREAMON` ioctl and the first read(), -write() and select() call. +:ref:`VIDIOC_STREAMON` ioctl and the first :ref:`read() ` +, :ref:`write() ` and :ref:`select() ` calls. VBI devices must implement both the :ref:`VIDIOC_G_FMT ` and :ref:`VIDIOC_S_FMT ` ioctl, even if :ref:`VIDIOC_S_FMT ` ignores all requests diff --git a/Documentation/linux_tv/media/v4l/func-open.rst b/Documentation/linux_tv/media/v4l/func-open.rst index 9598c0fd592e..705175be80e6 100644 --- a/Documentation/linux_tv/media/v4l/func-open.rst +++ b/Documentation/linux_tv/media/v4l/func-open.rst @@ -32,12 +32,12 @@ Arguments technicality, input devices still support only reading and output devices only writing. - When the ``O_NONBLOCK`` flag is given, the read() function and the - :ref:`VIDIOC_DQBUF ` ioctl will return the ``EAGAIN`` - error code when no data is available or no buffer is in the driver - outgoing queue, otherwise these functions block until data becomes - available. All V4L2 drivers exchanging data with applications must - support the ``O_NONBLOCK`` flag. + When the ``O_NONBLOCK`` flag is given, the :ref:`read() ` + function and the :ref:`VIDIOC_DQBUF ` ioctl will + return the ``EAGAIN`` error code when no data is available or no + buffer is in the driver outgoing queue, otherwise these functions + block until data becomes available. All V4L2 drivers exchanging data + with applications must support the ``O_NONBLOCK`` flag. Other flags have no effect. diff --git a/Documentation/linux_tv/media/v4l/open.rst b/Documentation/linux_tv/media/v4l/open.rst index c349575efc03..a3e39df91e9d 100644 --- a/Documentation/linux_tv/media/v4l/open.rst +++ b/Documentation/linux_tv/media/v4l/open.rst @@ -73,7 +73,8 @@ support all functions. However, in practice this never worked: this 'feature' was never used by applications and many drivers did not support it and if they did it was certainly never tested. In addition, switching a device node between different functions only works when -using the streaming I/O API, not with the read()/write() API. +using the streaming I/O API, not with the +:ref:`read() `/\ :ref:`write() ` API. Today each device node supports just one function.