From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (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 AAA4B7BAF9 for ; Thu, 4 Apr 2024 10:16:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712225816; cv=none; b=uQMtYBhC6j5SBIQENU8TD4NVEHlwg0dXWLqLiy/Ssu1LTDknuvp7dDLduNmLpcqEE+/YQgrkxapyXINn7dA97hMasZGZLbPtFTsSJib89gOTzxQS3hxYYNH3MLd3n46V17ch/xQb0Zq0zilwZ4l9BTt8AcnEhqu1LbUQSJzk68o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712225816; c=relaxed/simple; bh=YSKGc8cFfcdHVssQf0U+nzIPt4QX+29cuHWHQt0zZK0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=trHGBtrKi7p3SgsUz6XvaYj8VJPXAswREAMOU+AIQwqKEkIJPgboiBAbOAzwQnc4+r84RzTNS0jOKbje1x16F+Z20xykpJNm78E4usyHM4Gmo6VGcD7R5fwN/oM5koUSK8b/1znIdey8bQSONgqkySXyTZN/jog2YAyldmQc6AU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=FezlMupI; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="FezlMupI" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 44A571A2; Thu, 4 Apr 2024 12:16:15 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1712225775; bh=YSKGc8cFfcdHVssQf0U+nzIPt4QX+29cuHWHQt0zZK0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FezlMupIE+hoD+zs/79tdqjLryVoz+aRpxQmWvNuvI0itpyhRm7TVYcvFDZMEEoNc d/ddeFDk7AJnDn0EL//oFu7co9nvTLqC270ScNMiAI3CmAlt0cVD49d+iooXwLLNNV GNG9w5gSz8IU3zVtS417rVcxBy+QTdzCpeKhNawA= Date: Thu, 4 Apr 2024 13:16:41 +0300 From: Laurent Pinchart To: Hans Verkuil Cc: linux-media@vger.kernel.org, Sakari Ailus , Tomi Valkeinen Subject: Re: [PATCH] media: v4l2-subdev: Remove stream support for the crop API Message-ID: <20240404101641.GM23803@pendragon.ideasonboard.com> References: <20240403224233.18224-1-laurent.pinchart@ideasonboard.com> Precedence: bulk X-Mailing-List: linux-media@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Hi Hans, On Thu, Apr 04, 2024 at 10:27:49AM +0200, Hans Verkuil wrote: > On 04/04/2024 00:42, Laurent Pinchart wrote: > > When support for streams was added to the V4L2 subdev API, the > > v4l2_subdev_crop structure was extended with a stream field, but the > > field was not handled in the core code that translates the > > VIDIOC_SUBDEV_[GS]_CROP ioctls to the selection API. This could be > > fixed, but the crop API is deprecated and shouldn't be used by new > > userspace code. It's therefore best to avoid extending it with new > > features. Drop the stream field from the v4l2_subdev_crop structure, and > > update the documentation and kernel code accordingly. > > > > Fixes: 2f91e10ee6fd ("media: subdev: add stream based configuration") > > Signed-off-by: Laurent Pinchart > > --- > > This supersedes the "[PATCH] media: v4l2-subdev: Fix stream handling for > > crop API" patch ([1]). I'll submit matching patches for v4l2-compliance. > > > > [1] https://patchwork.linuxtv.org/project/linux-media/patch/20240401233725.2401-1-laurent.pinchart@ideasonboard.com/ > > --- > > .../userspace-api/media/v4l/vidioc-subdev-g-crop.rst | 5 +---- > > drivers/media/v4l2-core/v4l2-subdev.c | 6 ------ > > include/uapi/linux/v4l2-subdev.h | 4 +--- > > 3 files changed, 2 insertions(+), 13 deletions(-) > > > > diff --git a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst > > index 92d933631fda..7eeb7b553abf 100644 > > --- a/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst > > +++ b/Documentation/userspace-api/media/v4l/vidioc-subdev-g-crop.rst > > @@ -96,10 +96,7 @@ modified format should be as close as possible to the original request. > > - ``rect`` > > - Crop rectangle boundaries, in pixels. > > * - __u32 > > - - ``stream`` > > - - Stream identifier. > > - * - __u32 > > - - ``reserved``\ [7] > > + - ``reserved``\ [8] > > - Reserved for future extensions. Applications and drivers must set > > the array to zero. > > > > diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c > > index 4c6198c48dd6..02c2a2b472df 100644 > > --- a/drivers/media/v4l2-core/v4l2-subdev.c > > +++ b/drivers/media/v4l2-core/v4l2-subdev.c > > @@ -725,9 +725,6 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg, > > struct v4l2_subdev_crop *crop = arg; > > struct v4l2_subdev_selection sel; > > > > - if (!client_supports_streams) > > - crop->stream = 0; > > - > > memset(crop->reserved, 0, sizeof(crop->reserved)); > > memset(&sel, 0, sizeof(sel)); > > sel.which = crop->which; > > @@ -749,9 +746,6 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg, > > if (crop->which != V4L2_SUBDEV_FORMAT_TRY && ro_subdev) > > return -EPERM; > > > > - if (!client_supports_streams) > > - crop->stream = 0; > > - > > memset(crop->reserved, 0, sizeof(crop->reserved)); > > memset(&sel, 0, sizeof(sel)); > > sel.which = crop->which; > > diff --git a/include/uapi/linux/v4l2-subdev.h b/include/uapi/linux/v4l2-subdev.h > > index 7048c51581c6..f7eea12d8a2c 100644 > > --- a/include/uapi/linux/v4l2-subdev.h > > +++ b/include/uapi/linux/v4l2-subdev.h > > @@ -48,15 +48,13 @@ struct v4l2_subdev_format { > > * @which: format type (from enum v4l2_subdev_format_whence) > > * @pad: pad number, as reported by the media API > > * @rect: pad crop rectangle boundaries > > - * @stream: stream number, defined in subdev routing > > * @reserved: drivers and applications must zero this array > > */ > > struct v4l2_subdev_crop { > > __u32 which; > > __u32 pad; > > struct v4l2_rect rect; > > - __u32 stream; > > - __u32 reserved[7]; > > + __u32 reserved[8]; > > }; > > Sorry, but you can't remove this field. This field has been in the uAPI since > v6.3, and applications might be using it, even if only to set it to 0. Removing > this field will break compilation of such applications. No application should set it to anything else than 0, as stream support is disabled in the mainline kernel. However, even if I think the risk is very small, there is indeed a risk than an application may be setting it to 0. > Just fix the stream support instead, rather than removing it, as you did in > your original patch: > > https://lore.kernel.org/linux-media/20240401233725.2401-1-laurent.pinchart@ideasonboard.com/ We can also mark it as deprecated but stop short of removing it. > > > > #define V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE 0x00000001 > > > > base-commit: 39cd87c4eb2b893354f3b850f916353f2658ae6f -- Regards, Laurent Pinchart