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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 922ACC47088 for ; Mon, 5 Dec 2022 22:03:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232640AbiLEWDQ (ORCPT ); Mon, 5 Dec 2022 17:03:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37910 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232018AbiLEWDN (ORCPT ); Mon, 5 Dec 2022 17:03:13 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE4152C7; Mon, 5 Dec 2022 14:03:12 -0800 (PST) Received: from pendragon.ideasonboard.com (213-243-189-158.bb.dnainternet.fi [213.243.189.158]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 3C11C589; Mon, 5 Dec 2022 23:03:10 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1670277790; bh=R9c+OK/QPNRPg641/oRs3vSbSAY/lw4zvCkJ30yFVJU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=KM0GT23gcFzckrirUJPZHUHs8sNnm3m3U0umeR2qmWhQ4ecqIRp8gLbiiZTVTrbcu yhbF7p1qfmqPUlr+x6S0sGBmiZvk7hclhVdemSDBWlWNv3zl6MtZcRLgmJQIA6blHu xfvjPi5k0c2YjqG9U/JBvNyeToTmAfmTtzxI7gkc= Date: Tue, 6 Dec 2022 00:03:07 +0200 From: Laurent Pinchart To: Ricardo Ribalda Cc: Yunke Cao , Mauro Carvalho Chehab , Sergey Senozhatsky , linux-media@vger.kernel.org, Mauro Carvalho Chehab , linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 1/3] media: v4l2-dev.c: Add Meta: to the name of metadata devices Message-ID: References: <20220920-resend-meta-v4-0-3ac355b66723@chromium.org> <20220920-resend-meta-v4-1-3ac355b66723@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220920-resend-meta-v4-1-3ac355b66723@chromium.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ricardo, Thank you for the patch. On Fri, Dec 02, 2022 at 06:08:17PM +0100, Ricardo Ribalda wrote: > Devices with Metadata output (like uvc), create two video devices, one > for the data itself and another one for the metadata. > > Add a "Meta: " to the beginning of the device name, as suggested by Mauro, > to avoid having multiple devices with the same name. > > Fixes v4l2-compliance: > Media Controller ioctls: > fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end() > test MEDIA_IOC_G_TOPOLOGY: FAIL > fail: v4l2-test-media.cpp(394): num_data_links != num_links > test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL > > Suggested-by: Mauro Carvalho Chehab > Signed-off-by: Ricardo Ribalda > --- > drivers/media/v4l2-core/v4l2-dev.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c > index 397d553177fa..5c2c9ebb6b96 100644 > --- a/drivers/media/v4l2-core/v4l2-dev.c > +++ b/drivers/media/v4l2-core/v4l2-dev.c > @@ -901,6 +901,15 @@ int __video_register_device(struct video_device *vdev, > if (WARN_ON(type != VFL_TYPE_SUBDEV && !vdev->device_caps)) > return -EINVAL; > > + /* Add Meta: to metadata device names */ > + if (vdev->device_caps & > + (V4L2_CAP_META_CAPTURE | V4L2_CAP_META_OUTPUT)) { > + char aux[sizeof(vdev->name)]; > + > + snprintf(aux, sizeof(aux), "Meta: %s", vdev->name); This will break userspace I'm afraid. libcamera looks up video devices by entity names for multiple platforms. I wouldn't be surprised if other userspace applications did something similar. > + strscpy(vdev->name, aux, sizeof(aux)); > + } > + > /* v4l2_fh support */ > spin_lock_init(&vdev->fh_lock); > INIT_LIST_HEAD(&vdev->fh_list); > -- Regards, Laurent Pinchart