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 2F59E182A7; Wed, 7 Feb 2024 11:22:48 +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=1707304971; cv=none; b=Vf0i35u3WH1U0llJcEfIsILDPtGc/sI2CEhpqovZu/M2MCekAxHZjjaNxvwdcUEh+7s433oK2cyNGnmVNQnaqp64WRI/7w54/05oJY0u9CyFhWnGdruoRfTCrwMWv5vK0tqhJsoxuc/jO/EBVKKpVq899gFv+AB3Uir7QdgWtmM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707304971; c=relaxed/simple; bh=J35yOnxIj4zbmc/I04JW3XLI50tfpHXJ5MOqLVr19xM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=q19nUYFQpO6fCUG95ytE2LxGdz/uVuKi/jR8rpAgcDNG7ZRK0BcTFlUa20+QZc7KBftN+AW4o/p5GYqmksqF2LrfNfSQEoKXDBQqgpwfoIiFZcVk/gzDTIL1ISgd1PDl1n16/57mADHwZUu9WUGf8dfMF9pdfl/sG5Ow36G2zD4= 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=PjisdU24; 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="PjisdU24" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1707304967; bh=J35yOnxIj4zbmc/I04JW3XLI50tfpHXJ5MOqLVr19xM=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=PjisdU24hA0DWwqpNNg2aWhO7kUIgqelgh//n/DDdqu1CwcBrGC0Riu5+sfaUJuCZ Q+zmazaUVCRXHsR/8DvLl2Lb5nZp/IiKAEx6UeDxg2VVo1UwncCxdU7l64pRnBR8Fi JnsHi2fP1tqJ+VxVKGq+zTu1WAE7vC8/ZyilOxPajgv52W6vDqmvsQE4jxuhcZCmqy 5NvkfQlAQb0v0Qrn+OnCyOOGymlyc24xRcwNNl/P3hbaihnQIRWiPpKMHd8+0050pS egPYP8vcoyJzietLM6+ht3+5efft5EwrH5cKIjq8za1zmpjKu6eoiAVz+GlgByIYcA M9JLSvVa6/WpA== 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 1AC353782069; Wed, 7 Feb 2024 11:22:47 +0000 (UTC) Message-ID: Date: Wed, 7 Feb 2024 12:22:46 +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: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Le 07/02/2024 à 12:20, Hans Verkuil a écrit : > On 07/02/2024 12:15, Benjamin Gaignard wrote: >> 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 ? > Up to you, whatever makes the most sense. I will include it in DELETE_BUFS patch because it is strongly related to it. Regards, Benjamin > > Regards, > > Hans > >>> 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 >>> >>> >>>