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 B918F2DCF61; Tue, 3 Feb 2026 21:22:29 +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=1770153751; cv=none; b=tQ5jMMG4m/vXKKHnZ8+Sb6PRc8HmQfN1m294/eKgb0588WMCfcpUoDoaixPWuD58NJ5QED5vH9aG2TugOEK6lOW3l4O1k9bidQnkXFXXOku6ruWLVACOUIOUp1iB94khggS6yO6r3Z5an1przPhJAxA+3sSPRbQaCbdeulK9B3Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770153751; c=relaxed/simple; bh=/g5zX3YPTqscDXF6T3zgPUZtSMHSuRj/OQ9EbVXsZ+k=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=A4HAYeJeCgArNj5/WeuHCFdn5pR7NxJf5piHIZRitjtJ1wW7H43JBf27p1SkspqFF6MxQwfOdRFaraW1FMfKTgXjGXj3gqImEsbTqc53CBq2oO7XX24/wQQULyte4wEaekF7iLIUwYtwlSj5AymWvKIclhQr4Jmwdqxldo4aE0I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=R/6G2dPD; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="R/6G2dPD" Received: from killaraus.ideasonboard.com (2001-14ba-703d-e500--2a1.rev.dnainternet.fi [IPv6:2001:14ba:703d:e500::2a1]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id 30C11673; Tue, 3 Feb 2026 22:21:46 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1770153706; bh=/g5zX3YPTqscDXF6T3zgPUZtSMHSuRj/OQ9EbVXsZ+k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=R/6G2dPDW37zaHdjkWiIcCSfsJWXrt5pi9kOv7rPrswcUyfL8APMHbRJ8K1VbPsJE Hf75leh0o9rGe/nGSWU/Goh15/2vCZqyRcY8Ux/EfKjivzxdYCZYjrEPn2fjR/1fox Ad8r2mtl0KKF98qKzJIXdLsMP8yurvrWk2Bpm084= Date: Tue, 3 Feb 2026 23:22:26 +0200 From: Laurent Pinchart To: Jarkko Sakkinen 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: <20260203212226.GF11369@killaraus> References: <20260202204425.2614054-1-jarkko@kernel.org> <6b192c71-c389-4a6e-b7c3-ddcd5cc4aa34@oss.qualcomm.com> <37a0d91c2e78c97f3d956444c4f7a2a2fca9ae06@intel.com> <2bda02cb3da6cb6ca7dcf545a5b7af27fb7a6e37@intel.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: 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. > That also does make difference as there are some guarantees that the > end product would not be left into rotten. -- Regards, Laurent Pinchart