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=-8.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 3FF93C3A5A9 for ; Mon, 4 May 2020 13:36:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E046D2078E for ; Mon, 4 May 2020 13:36:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=xs4all.nl header.i=@xs4all.nl header.b="H7Q6n9wN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728035AbgEDNgt (ORCPT ); Mon, 4 May 2020 09:36:49 -0400 Received: from lb2-smtp-cloud8.xs4all.net ([194.109.24.25]:35279 "EHLO lb2-smtp-cloud8.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726404AbgEDNgt (ORCPT ); Mon, 4 May 2020 09:36:49 -0400 Received: from cust-b5b5937f ([IPv6:fc0c:c16d:66b8:757f:c639:739b:9d66:799d]) by smtp-cloud8.xs4all.net with ESMTPA id VbGzjO5j8hEkrVbH3jumWh; Mon, 04 May 2020 15:36:46 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=xs4all.nl; s=s1; t=1588599406; bh=gS3mEk/hXH4UjyuO6mtimQUI4NpdzupkxnK75I3D7NI=; h=Subject:To:From:Message-ID:Date:MIME-Version:Content-Type:From: Subject; b=H7Q6n9wN/XxKZSj7GKH8sUVx7OnIgilHElfNHLzU1wQjA/zsP2aJ0p347Feo8bpto hpxhCINw2ADmXch4db/K0mpsmhEisffQr6w2NiSMc7s4kBbJbN+gjNvXUvmXun8bkL 7NaCv32jrvCzp/miUgWeGhfU827wyQ11qix2DyKbCopwR4p07f46DExDA2iud9zW8q bU79ThN3529ti8juDxbqH8W/G2d8n+Aeapmv4KmG0VWsVsVhEUfjVxWvcoCvEeFV0g l8dnd7MoW2grJ9VB/wEe2jKXLeK7nGz1ODSL8drFKQtaB8rnknhcGOBgQ6b0YgqVUj orL9PXY+Bym2Q== Subject: Re: [PATCH v2 32/34] media: videobuf2: Allow exporting of a struct dmabuf To: Laurent Pinchart , linux-media@vger.kernel.org Cc: Kieran Bingham , Jacopo Mondi , =?UTF-8?Q?Niklas_S=c3=b6derlund?= , Naushir Patuck , Dave Stevenson , Dave Stevenson References: <20200504092611.9798-1-laurent.pinchart@ideasonboard.com> <20200504092611.9798-33-laurent.pinchart@ideasonboard.com> From: Hans Verkuil Message-ID: <75f625a4-947d-6af6-38cd-49b5cb2a58a9@xs4all.nl> Date: Mon, 4 May 2020 15:36:41 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <20200504092611.9798-33-laurent.pinchart@ideasonboard.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-CMAE-Envelope: MS4wfA+TE3EIN9MJADF8uyauRRI8HH2oLVWf8jm9PwUH1fCSuhwwCEjFDOB5dvVd+0Dr2fTLb09EZQR1D2yRpKyPYlg+pgjgFhwBvDRSdo8NzUutw2t6jVfj Zyqa7tMd71pWma+5VHOk0wc5x/vh6z0M+YArEyfqqjajY4GrMBzj295FOUvcQwe1UvJV/ohJf6MWWoQN/J1keM0hpzs+As6628QkPPQCVL2eW9GI6c9wpRBv x4gkYqFjLIIdVvB0S4vaTjC8Wj4TOBd8/sCqSscV9tX6F+IELZKvYxLc20y2yVHqBZYs3UwCMp5zvJeH8/WRaVLrhEUtYj8K+cBTpZPlJkt5K2hV5iCUzaT8 94tDFAgKP7l71XkoO81yyGhsnnooIuSvqPjWjDMm686FJH5igX9rONJwu7WH8cHU19sC9YUssEvwODPdRxNKji3GK5hGI5mdk+zF91geY211n03jHOk= Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On 04/05/2020 11:26, Laurent Pinchart wrote: > From: Dave Stevenson > > videobuf2 only allowed exporting a dmabuf as a file descriptor, > but there are instances where having the struct dma_buf is > useful within the kernel. > > Split the current implementation into two, one step which > exports a struct dma_buf, and the second which converts that > into an fd. > > Signed-off-by: Dave Stevenson > --- > .../media/common/videobuf2/videobuf2-core.c | 21 ++++++++++++++++--- > include/media/videobuf2-core.h | 15 +++++++++++++ > 2 files changed, 33 insertions(+), 3 deletions(-) > > diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c > index 44d65f5be845..befdc89983e2 100644 > --- a/drivers/media/common/videobuf2/videobuf2-core.c > +++ b/drivers/media/common/videobuf2/videobuf2-core.c > @@ -2073,12 +2073,12 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, > return -EINVAL; > } > > -int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, > - unsigned int index, unsigned int plane, unsigned int flags) > +int vb2_core_expbuf_dmabuf(struct vb2_queue *q, unsigned int type, > + unsigned int index, unsigned int plane, > + unsigned int flags, struct dma_buf **dmabuf) Just returning struct dma_buf and using ERR_PTR() to report errors would be much more elegant. Otherwise this patch is fine. Regards, Hans > { > struct vb2_buffer *vb = NULL; > struct vb2_plane *vb_plane; > - int ret; > struct dma_buf *dbuf; > > if (q->memory != VB2_MEMORY_MMAP) { > @@ -2128,6 +2128,21 @@ int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, > return -EINVAL; > } > > + *dmabuf = dbuf; > + return 0; > +} > +EXPORT_SYMBOL_GPL(vb2_core_expbuf_dmabuf); > + > +int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, > + unsigned int index, unsigned int plane, unsigned int flags) > +{ > + struct dma_buf *dbuf; > + int ret; > + > + ret = vb2_core_expbuf_dmabuf(q, type, index, plane, flags, &dbuf); > + if (ret) > + return ret; > + > ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE); > if (ret < 0) { > dprintk(3, "buffer %d, plane %d failed to export (%d)\n", > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index f11b96514cf7..86920d3264ab 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -875,6 +875,21 @@ int vb2_core_streamon(struct vb2_queue *q, unsigned int type); > */ > int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); > > +/** > + * vb2_core_expbuf_dmabuf() - Export a buffer as a dma_buf structure > + * @q: videobuf2 queue > + * @type: buffer type > + * @index: id number of the buffer > + * @plane: index of the plane to be exported, 0 for single plane queues > + * @flags: flags for newly created file, currently only O_CLOEXEC is > + * supported, refer to manual of open syscall for more details > + * @dmabuf: Returns the dmabuf pointer > + * > + */ > +int vb2_core_expbuf_dmabuf(struct vb2_queue *q, unsigned int type, > + unsigned int index, unsigned int plane, > + unsigned int flags, struct dma_buf **dmabuf); > + > /** > * vb2_core_expbuf() - Export a buffer as a file descriptor. > * @q: pointer to &struct vb2_queue with videobuf2 queue. >