From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DCD51C433E0 for ; Thu, 23 Jul 2020 08:10:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BB276206D7 for ; Thu, 23 Jul 2020 08:10:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=xs4all.nl header.i=@xs4all.nl header.b="RcM+VRiD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726764AbgGWIKm (ORCPT ); Thu, 23 Jul 2020 04:10:42 -0400 Received: from lb3-smtp-cloud9.xs4all.net ([194.109.24.30]:47743 "EHLO lb3-smtp-cloud9.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725858AbgGWIKm (ORCPT ); Thu, 23 Jul 2020 04:10:42 -0400 Received: from cust-b5b5937f ([IPv6:fc0c:c16d:66b8:757f:c639:739b:9d66:799d]) by smtp-cloud9.xs4all.net with ESMTPA id yWJHjzu6MuuXOyWJIj8xiI; Thu, 23 Jul 2020 10:10:39 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xs4all.nl; s=s1; t=1595491839; bh=S4EgoCbBmTgeGbV3FNpEwzrs8Seq7SlB0q88PTB/Mg4=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type:From: Subject; b=RcM+VRiD8st0V/BJSf2L9MvhUo0T8OyRhqfznuVlPCajuoUlCnjB+2Z4FDo/qPraQ Jc9L1m3XOA7bSxoFe3VUP9FRh130sr07z79w51IRnUlgXp8elE7boYyu0R9NDRC6ty VD2fZx4HimeIgxOnL1lC0SuWfIf5b47hpaHqi2Cs7tFWCXN3DybD8XpGXosfoNhZOU TUTvJS3k7LTRKjElL9LC8h7RFTFo/V7nh1geXg1mhaZ4Ik0uKt1xGk9iPIIU9wXuwT 4Sw+HeFsvhs7ozb2AQWCp0u94SpMvLNXm6fZJ1dtC4+NICYAyGsE95rG6T424CZgcW g1P2h4N2m3l1A== Subject: Re: [PATCH v3,1/2] media: v4l UAPI: add V4L2_BUF_CAP_SUPPORTS_RO_REQUESTS To: Yunfei Dong , Tiffany Lin , Rob Herring Cc: Mauro Carvalho Chehab , Mark Rutland , Matthias Brugger , linux-media@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, Tomasz Figa , Alexandre Courbot References: <20200701093522.8521-1-yunfei.dong@mediatek.com> <20200701093522.8521-2-yunfei.dong@mediatek.com> From: Hans Verkuil Message-ID: <047b49b0-53d4-3ddf-e629-1686a6d4eb31@xs4all.nl> Date: Thu, 23 Jul 2020 10:10:35 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20200701093522.8521-2-yunfei.dong@mediatek.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4wfFQN2IYlI+0IepjRuZ70GgrkpY9Ngx0UU6k7lKmM0epEF1LWTvJfQyRbUzdemzReVKMEfVECkSDwUvHCFqmC6WMTFU9/qdfF+EpUapAgHTBNveCH/J6N nK0IDmGmDsoRpHl7xhiH/Bz4mofLIkVPScuqHc2kMFhfE2eoYNdtXbnpfgwfrZDVVA/IGWIN5z8i2lAWY7qBwzETEzVoWtMgxjM1vplYXWvv3lXbKi7ETxm6 6QHvYAKqYhVStAtKkFeyFDOBHDLXEf8gpuDdsnNbbIQ02HC9zjz/W7ihTVdV2RaQ19lAZboxNUh7wdGr6m9+N5gGE+5wbpVw0cRz+4SZxUogco0tbkvwB4ZN EzW4ZDP5oQmwg+fA7nU68gleNtparGKVRvI1PmpqV1JualWfAvMAoFbJFgRSvs9Ws3WGMr+mqZGQB4/7Q6onnvwZay9aQ1wsK25IJOuvebncPdHgicn6oSbw LavBgbF6lhFEZ247AQerScfwAdjxvQ5YiRP6zp9cYbwAp1dCvhq1HPHHB7lNUQCVif9uX5aJCg/SWAW//v7OEapSGpa+uIKQ1gJR1rpZuUtDENL+1Dx3Jz/S oaPd6qO95uTtcPmmGS936jCgdoUSuD0iloZ2cKGp1yLzKQrI/3pvMsXXB1aFqzTTUxM0ABDsw7SdO+I9EE6azUpGamhAe8wMD3ud3hrShZc3jxyExKk2OoHE W6UVMGaaACw= Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/07/2020 11:35, Yunfei Dong wrote: > This patch adds support for the V4L2_BUF_CAP_SUPPORTS_RO_REQUESTS > flag. This flag is used for Read-only(Ro) Request. > > Signed-off-by: Yunfei Dong > --- > Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst > index b6d52083707b..7c7451773b8e 100644 > --- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst > +++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst > @@ -126,6 +126,7 @@ aborting or finishing any DMA in progress, an implicit > .. _V4L2-BUF-CAP-SUPPORTS-REQUESTS: > .. _V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS: > .. _V4L2-BUF-CAP-SUPPORTS-M2M-HOLD-CAPTURE-BUF: > +.. _V4L2-BUF-CAP-SUPPORTS-RO-REQUESTS: > > .. cssclass:: longtable > > @@ -156,6 +157,9 @@ aborting or finishing any DMA in progress, an implicit > - Only valid for stateless decoders. If set, then userspace can set the > ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag to hold off on returning the > capture buffer until the OUTPUT timestamp changes. > + * - ``V4L2_BUF_CAP_SUPPORTS_RO_REQUESTS`` > + - 0x00000040 > + - This buffer type supports :ref:`requests `. This is wrong, it supports *read-only* requests. Also, Documentation/userspace-api/media/mediactl/request-api.rst should mention read-only requests: I think a new section "Read-Only Requests" explaining the purpose and use of such requests would be best. It can be inserted just before the "Example for a Codec Device" at the end. Regards, Hans > > Return Value > ============ >