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=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 93B1DC33CA2 for ; Fri, 10 Jan 2020 09:46:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 671E22080D for ; Fri, 10 Jan 2020 09:46:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="ORb+fnTI" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727354AbgAJJqK (ORCPT ); Fri, 10 Jan 2020 04:46:10 -0500 Received: from mail-pj1-f65.google.com ([209.85.216.65]:33043 "EHLO mail-pj1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727310AbgAJJqK (ORCPT ); Fri, 10 Jan 2020 04:46:10 -0500 Received: by mail-pj1-f65.google.com with SMTP id u63so1755713pjb.0 for ; Fri, 10 Jan 2020 01:46:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=kVXjETvA9K8/lP9ZBnbh1cVxAMGV1mSFPntHWPphT5k=; b=ORb+fnTIv6NoPl8sJCI+ZXc5y2kRw21j1E60VarEzwIjLsD3zEzDM192gZFBtTCzqK IdZZLjTJ85iEnkB+4D+TOJrapLFlSrRYTTZcO6L7/AhuRkhMUSdIyluFU0Z3EbAFnQ9i UrmTHtVePJjVBoQCXvdjEiyTlg7PpL4JbelIs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=kVXjETvA9K8/lP9ZBnbh1cVxAMGV1mSFPntHWPphT5k=; b=BjmSN/Va8+zGcF1MSHvqFZ+eVtyzOiWAtRm1+Kh5ue31fJAhmSuLSBdmA709v2zYXZ 1nWqj5vSYIfBwhKSaXK7sEXRpeFh+w8QILGZUdw4VN82mA1RsH/L21LHLp4zFhq6uXAL n7vQbWnxNTLoBSagrYiBC0RqgqXywWVFZrLWqGC210poHz57M0oUtgSdK8fvz7FSuXcv HcmlRCoYwKEIlHGGxIRTpiUz1EPI+25zbf7ZQBVfPklF9GE7MLBqg0rpBy30Jr+znBP4 UrhKObc4++N9bQODcGE41QLSb7gWr+ypnjmI+qH3tYxENDKh6UvPawtcKT7XEy59fGjd u4dQ== X-Gm-Message-State: APjAAAX/bMfZvpVPX9EXoZYQcLQ1bBYPwnGVo8YNPbMQjIA2qK25iJLf igoYS+EAEUd9WDDcXhsgQcRFUA== X-Google-Smtp-Source: APXvYqzjIJ8v2NA2EXA8o0hEnespVu1na2a2y1A+8wSnIYd+HWQ7dqrnrEH4SIcmpRMCF3yimeILyw== X-Received: by 2002:a17:90b:f06:: with SMTP id br6mr3525192pjb.125.1578649569314; Fri, 10 Jan 2020 01:46:09 -0800 (PST) Received: from localhost ([2401:fa00:8f:203:250d:e71d:5a0a:9afe]) by smtp.gmail.com with ESMTPSA id g2sm2059453pgn.59.2020.01.10.01.46.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jan 2020 01:46:08 -0800 (PST) Date: Fri, 10 Jan 2020 18:46:07 +0900 From: Sergey Senozhatsky To: Hans Verkuil Cc: Sergey Senozhatsky , Hans Verkuil , Tomasz Figa , Mauro Carvalho Chehab , Kyungmin Park , Marek Szyprowski , Sakari Ailus , Laurent Pinchart , Pawel Osciak , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH 03/15] videobuf2: add V4L2_FLAG_MEMORY_NON_CONSISTENT flag Message-ID: <20200110094607.GB202391@google.com> References: <20191217032034.54897-1-senozhatsky@chromium.org> <20191217032034.54897-4-senozhatsky@chromium.org> <750a0c62-0f0f-a5c9-1d7f-f0c5d6b620fa@xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <750a0c62-0f0f-a5c9-1d7f-f0c5d6b620fa@xs4all.nl> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (20/01/10 10:36), Hans Verkuil wrote: [..] > > diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst > > index 9149b57728e5..b08b5609f5f3 100644 > > --- a/Documentation/media/uapi/v4l/buffer.rst > > +++ b/Documentation/media/uapi/v4l/buffer.rst > > @@ -705,6 +705,25 @@ Buffer Flags > > > > .. c:type:: v4l2_memory > > > > +Memory Consistency Flags > > +======================== > > + > > +.. tabularcolumns:: |p{7.0cm}|p{2.2cm}|p{8.3cm}| > > + > > +.. cssclass:: longtable > > + > > +.. flat-table:: > > + :header-rows: 0 > > + :stub-columns: 0 > > + :widths: 3 1 4 > > + > > + * .. _`V4L2_FLAG_MEMORY_NON_CONSISTENT`: > > + > > + - ``V4L2_FLAG_MEMORY_NON_CONSISTENT`` > > + - 0x00000001 > > + - Set DMA_ATTR_NON_CONSISTENT queue memory consistency bit, > > + so all queue buffers may be allocated in non-consistent memory. > > This needs much more extensive documentation. This is a userspace API, > and it shouldn't refer to a kernelspace API. Instead, explain what it > means from a user perspective. Also, how does this relate to the cache > buffer flags? > > These things are tricky, so it is worth spending some time on writing > good documentation. Agreed. I'll give it a shot, will try to improve it. -ss