From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from madrid.collaboradmins.com (madrid.collaboradmins.com [46.235.227.194]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CEF3D1B7F7; Wed, 7 Feb 2024 11:15:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.235.227.194 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707304506; cv=none; b=o88AUaJdw9ID2X5CgK+jcLQeJXTXDeUmUSrZ3cRFd03F5IFinuPhQiSJf0dWuY+mQ43+pEPMwMLIqnRDwhUe24nnTvOzzK1RQk1t6NXtYVgSBlyu0/JVHR5Uf8K+/fLgEbRo/WJJB4WQ6jyROW83I6D00waZ5VSivCj0kf7FIM0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707304506; c=relaxed/simple; bh=dqFNplGDYGhi0vuOVY8SahUo4rLkXBsaOf5qz5o2pNw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=E9We8gkm67w86mkvm1/gUE1Uw9CoBn+3aO8WwqLhXu607kWMYgGQocy+TIxjFBwAHyF7wIr959tzP41TI9zVa/mO1mgqrhXhXJSWg3f0m5czapK1USlQM/fzC/aqhsDYxFZhPc25behpHFElojR0aF+wDIznerhWPfksb07EfF4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=T5L1qWfb; arc=none smtp.client-ip=46.235.227.194 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="T5L1qWfb" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1707304503; bh=dqFNplGDYGhi0vuOVY8SahUo4rLkXBsaOf5qz5o2pNw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=T5L1qWfbnoNThDtC+nLW33z+FTcixzR/LCkv/hS41Fu5J4SZW1j9UYuUfPCbM6CxT 3pDtVSW/IP20GS0c4XVtmsk8x1CnMNeHyjqzzKvoJUy8suukaRj/HbF1U1NFIqwk3u KeDa8qMr4MloVa/ydVEpl5E5TUOybAE+qKU2yG30pSFo2CEdQ0kn/V8yQ2N8Wo+cdb QlmnZbdJkyq/AsdHvQqFMIJYsV9ZCYLQ7dVifbEXFhrJIP9QVY4Xyc47dcWzLGWYN3 dDRR81skduOIO0ZqCoIPB6SqVVKscobFq4CxVrfKvFggxl8tuB7TDaaZyT1opZkKqI 21EWCKgNKo+Kg== Received: from [100.93.89.217] (cola.collaboradmins.com [195.201.22.229]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: benjamin.gaignard) by madrid.collaboradmins.com (Postfix) with ESMTPSA id A94A13782069; Wed, 7 Feb 2024 11:15:02 +0000 (UTC) Message-ID: Date: Wed, 7 Feb 2024 12:15:02 +0100 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v19 0/9] Add DELETE_BUF ioctl Content-Language: en-US To: Hans Verkuil , mchehab@kernel.org Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, kernel@collabora.com References: <20240206080219.11951-1-benjamin.gaignard@collabora.com> <67823e2e-9d60-4c08-bdd1-c974aaf96a93@xs4all.nl> From: Benjamin Gaignard In-Reply-To: <67823e2e-9d60-4c08-bdd1-c974aaf96a93@xs4all.nl> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Le 07/02/2024 à 10:12, Hans Verkuil a écrit : > Hi Benjamin, > > On 06/02/2024 09:58, Hans Verkuil wrote: >> On 06/02/2024 09:02, Benjamin Gaignard wrote: >>> Unlike when resolution change on keyframes, dynamic resolution change >>> on inter frames doesn't allow to do a stream off/on sequence because >>> it is need to keep all previous references alive to decode inter frames. >>> This constraint have two main problems: >>> - more memory consumption. >>> - more buffers in use. >>> To solve these issue this series introduce DELETE_BUFS ioctl and remove >>> the 32 buffers limit per queue. >> This v19 looks good. There are three outstanding issues that I need to take a >> look at: >> >> 1) Can we still signal support for DELETE_BUFS in the V4L2_BUF_CAP_ caps? >> It would be nice to have, but I'm not sure if and how that can be done. > So, I came up with the following patch to add back the V4L2_BUF_CAP_SUPPORTS_DELETE_BUFS > capability. If the DELETE_BUFS ioctl is valid, then it sets this capability > before calling vidioc_reqbufs or vidioc_create_bufs. So right now it will set > this for any queue. If we ever want to disable this for a specific queue, then > either the driver has to override these two ops and clear the flag, or a new > vb2_queue flag (e.g. disable_delete_bufs) is added and vb2_set_flags_and_caps() > will clear that capability based on that flag. > > In any case, for now just set it for both queues by default. > > If you agree that this is a good way to proceed, then can you incorporate this > into a v20? You can add the documentation for this cap from the v17 version. Do you want it to be a separate patch or included in the patch introducing DELETE_BUFS ioctl ? > > Regards, > > Hans > > Signed-off-by: Hans Verkuil > --- > diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c > index 8e437104f9c1..64f2d662d068 100644 > --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c > +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c > @@ -685,7 +685,7 @@ static void vb2_set_flags_and_caps(struct vb2_queue *q, u32 memory, > *flags &= V4L2_MEMORY_FLAG_NON_COHERENT; > } > > - *caps = V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS; > + *caps |= V4L2_BUF_CAP_SUPPORTS_ORPHANED_BUFS; > if (q->io_modes & VB2_MMAP) > *caps |= V4L2_BUF_CAP_SUPPORTS_MMAP; > if (q->io_modes & VB2_USERPTR) > diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index a172d33edd19..45bc705e171e 100644 > --- a/drivers/media/v4l2-core/v4l2-ioctl.c > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c > @@ -2100,6 +2100,7 @@ static int v4l_overlay(const struct v4l2_ioctl_ops *ops, > static int v4l_reqbufs(const struct v4l2_ioctl_ops *ops, > struct file *file, void *fh, void *arg) > { > + struct video_device *vfd = video_devdata(file); > struct v4l2_requestbuffers *p = arg; > int ret = check_fmt(file, p->type); > > @@ -2108,6 +2109,9 @@ static int v4l_reqbufs(const struct v4l2_ioctl_ops *ops, > > memset_after(p, 0, flags); > > + if (is_valid_ioctl(vfd, VIDIOC_DELETE_BUFS)) > + p->capabilities = V4L2_BUF_CAP_SUPPORTS_DELETE_BUFS; > + > return ops->vidioc_reqbufs(file, fh, p); > } > > @@ -2141,6 +2145,7 @@ static int v4l_dqbuf(const struct v4l2_ioctl_ops *ops, > static int v4l_create_bufs(const struct v4l2_ioctl_ops *ops, > struct file *file, void *fh, void *arg) > { > + struct video_device *vfd = video_devdata(file); > struct v4l2_create_buffers *create = arg; > int ret = check_fmt(file, create->format.type); > > @@ -2151,6 +2156,9 @@ static int v4l_create_bufs(const struct v4l2_ioctl_ops *ops, > > v4l_sanitize_format(&create->format); > > + if (is_valid_ioctl(vfd, VIDIOC_DELETE_BUFS)) > + create->capabilities = V4L2_BUF_CAP_SUPPORTS_DELETE_BUFS; > + > ret = ops->vidioc_create_bufs(file, fh, create); > > if (create->format.type == V4L2_BUF_TYPE_VIDEO_CAPTURE || > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index 03443833aaaa..da307f46f903 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -1036,6 +1036,7 @@ struct v4l2_requestbuffers { > #define V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF (1 << 5) > #define V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS (1 << 6) > #define V4L2_BUF_CAP_SUPPORTS_MAX_NUM_BUFFERS (1 << 7) > +#define V4L2_BUF_CAP_SUPPORTS_DELETE_BUFS (1 << 8) > > /** > * struct v4l2_plane - plane info for multi-planar buffers > > >