From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B96D133985A; Tue, 3 Feb 2026 21:40:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770154833; cv=none; b=NtpfrcH5DBIJq5AP4sRvjp45C7dd805AYln/0jF9OXDMDOh5YssWKnU47K/rtllVmmL7ZpG1phQtSd4aewWK3FqthWqZGoF7UnYBui12GN/l9Pgx10xoqr2fVka90pSNFKDzkuC0GxyJDRqJR52HlIIBmP/XYeZvpuB7/v0cExk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770154833; c=relaxed/simple; bh=xk6hSF5V+5b2PHodbBhcUfr7/vd2d7OrNJYmZhHpJtg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=cEkWGKROUiZj46lBWsVVTlLk4Um1p/MVgHcUFNIYYbaUi56mwcBK03o6ItVFh+4A2kPpcIQ6DIE0boxBiC3T81qtRsuQ14imME+9SZrXCRqYwwHjP85gQ9ZDFgvCKakD6wH9RUD2/x/LYPvWjZXisu30sNeDUG3B8LY1IJR/b4E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=n2k+KUSC; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="n2k+KUSC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A1E4C116D0; Tue, 3 Feb 2026 21:40:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770154833; bh=xk6hSF5V+5b2PHodbBhcUfr7/vd2d7OrNJYmZhHpJtg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=n2k+KUSCQGS2HIl4lOxN6SSEJHrKToFPcCZ378Qj8QaaJ7omGy6OoiCE9HzIXHZT1 FNXu428ovxNgTejVZICaeMynyXsZx2XwNXhKPx0npX6ULP+tEyJv0orAUIel0ebEaU 7/StXeti70dowR9YNsU1HDZfBb+/6PcwKHlzZxpjViZMSv7C4nxuCZY8M/f8QDHWNT mq7TMmsaihRmMqdzJL2/8ckDvp2fX9VkRxQKEpTbiuyymCGit6bisXLVbsmK7syO5z bOAO7pSBBYN3Hy+/XA11QkfZHVouSGKDhEUUUSkelrUPW6nntZK2cLWe224+Hznhmp IDOrpTzg7gmuw== Date: Tue, 3 Feb 2026 23:40:30 +0200 From: Jarkko Sakkinen To: Laurent Pinchart Cc: Jani Nikula , johannes.goede@oss.qualcomm.com, linux-media@vger.kernel.org, anisse@astier.eu, oleksandr@natalenko.name, linux-integrity@vger.kernel.org, Mauro Carvalho Chehab , Hans Verkuil , Sakari Ailus , Jacopo Mondi , Ricardo Ribalda , open list Subject: Re: [RFC PATCH v2] media: Virtual camera driver Message-ID: References: <20260202204425.2614054-1-jarkko@kernel.org> <6b192c71-c389-4a6e-b7c3-ddcd5cc4aa34@oss.qualcomm.com> <37a0d91c2e78c97f3d956444c4f7a2a2fca9ae06@intel.com> <2bda02cb3da6cb6ca7dcf545a5b7af27fb7a6e37@intel.com> <20260203212226.GF11369@killaraus> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260203212226.GF11369@killaraus> On Tue, Feb 03, 2026 at 11:22:26PM +0200, Laurent Pinchart wrote: > On Tue, Feb 03, 2026 at 09:15:36PM +0200, Jarkko Sakkinen wrote: > > On Tue, Feb 03, 2026 at 09:07:41PM +0200, Jarkko Sakkinen wrote: > > > On Tue, Feb 03, 2026 at 08:53:13PM +0200, Jani Nikula wrote: > > > > On Tue, 03 Feb 2026, johannes.goede@oss.qualcomm.com wrote: > > > > > OTHO evdi: https://github.com/DisplayLink/evdi has been kept out > > > > > of the kernel for pretty much the same reasons by the drm/kms folks. > > > > > > > > > > At least AFAIK there still is no way to present virtual kms capable > > > > > display outputs backed by userspace in the kernel. > > > > > > > > > > I completely understand where you're coming from wrt v4l2-loopback > > > > > support (or something equivalent) but asking for this really is > > > > > the same as asking for the evdi driver to get merged, which AFAIK > > > > > has been blocked for the reason of avoiding proprietary userspace > > > > > display output drivers (I guess there might be technical reasons too). > > > > > > > > I'm not sure this is the same thing, though. > > > > > > > > The DRM subsystem does require an open source userspace for new uAPI, > > > > which is stricter than most subsystems [1]. Other than that, I don't > > > > think anyone's actively keeping evdi out of the kernel. AFAIK there > > > > hasn't been a serious attempt at upstreaming it either. Which is pretty > > > > much because there's no open userspace. Nobody's cared enough to either > > > > write one or open source the existing one for a decade [2]. > > > > > > This is unrelated of ACK/NACK and not saying this as a "selling point" > > > but realistically speaking based on what I've read I have extremely hard > > > time to believe that my driver would enable a market of proprietary > > > camera drivers :-) Actually, after looking up mipi.org based on Hans > > > response, I even more so believe that this is the case. > > > > With my maintainer hat on, I'd get the nack better if the driver was > > intrusive on changes to V4L2 subsystem itself. Then, it accumlates > > weight to other maintainers, and as we all have limited amount of time > > in our lives, I do get that. But since the driver would be compliance > > aligning leaf driver with a MAINTAINER entry of its own, it should not > > be a huge burden for V4L2 community and kernel maintainers. And I do > > have a track record of being long-term on maintaining stuff that I vomit > > out. > > I don't dispute that. Even though we haven't really worked together on > kernel development, I have no prejudice towards your commitment as a > driver maintainer :-) There's nothing personal in this mail thread. Absolutely non taken either (and neither from my side). > > > That also does make difference as there are some guarantees that the > > end product would not be left into rotten. > > -- > Regards, > > Laurent Pinchart BR, Jarkko