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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 903BFCAC58E for ; Thu, 11 Sep 2025 21:52:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6352A10EB95; Thu, 11 Sep 2025 21:52:24 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="qt75zUel"; dkim-atps=neutral Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by gabe.freedesktop.org (Postfix) with ESMTP id AFB4F10E12D for ; Thu, 11 Sep 2025 16:28:29 +0000 (UTC) Received: from [100.79.161.103] (unknown [4.194.122.162]) by linux.microsoft.com (Postfix) with ESMTPSA id 9C6502114256; Thu, 11 Sep 2025 09:28:25 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 9C6502114256 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1757608108; bh=quIaHEoArFCMUcQf+paMTNKIBoUq+EvYzrp1oocNIy4=; h=Date:Subject:To:References:From:In-Reply-To:From; b=qt75zUelG7lsCEsZuinBBzU/XjSbc2hjtJXC0bASVLC2SeAfKjEXkckmOh9I9nx7D bGeb6XMLfSa/RYpaUmmTSmvUXzQVzXtlPjjMOVMpWhJKLqRFmeZKIRO/nDrLWTDNYI vgK/hrRZkO68GWeo8oacIcmC1IIBTR22l+y41yE4= Message-ID: Date: Thu, 11 Sep 2025 21:58:23 +0530 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC 1/3] fbdev: hyperv_fb: Remove hyperv_fb driver To: Michael Kelley , Thomas Zimmermann , "deller@gmx.de" , "arnd@arndb.de" , "soci@c64.rulez.org" , "gonzalo.silvalde@gmail.com" , "rdunlap@infradead.org" , "bartosz.golaszewski@linaro.org" , "wei.liu@kernel.org" , "ssengar@linux.microsoft.com" , "linux-kernel@vger.kernel.org" , "linux-fbdev@vger.kernel.org" , "dri-devel@lists.freedesktop.org" References: <1757437112-2509-1-git-send-email-ptsm@linux.microsoft.com> <8a958fe8-fbba-4bd6-a79d-fd310f08f8d7@suse.de> Content-Language: en-US From: Prasanna Kumar T S M In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Mailman-Approved-At: Thu, 11 Sep 2025 21:52:23 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Hi Michael, On 10-09-2025 20:55, Michael Kelley wrote: > From: Thomas Zimmermann Sent: Wednesday, September 10, 2025 2:36 AM >> >> Hi >> >> Am 09.09.25 um 18:58 schrieb Prasanna Kumar T S M: >>> The Hyper-V DRM driver is available since kernel version 5.14 and >>> provides full KMS support along with fbdev emulation via the DRM fbdev >>> helpers. This makes the hyperv_fb driver redundant, remove it. >> >> I'm all for removing obsolete drivers. But hyperv_drm likely first needs >> to merge the patch at >> https://lore.kernel.org/dri-devel/20250904145806.430568-5-tzimmermann@suse.de/ >> It's been tested and works well. If maintainers from Microsoft have a >> look at the patch first, we could possibly land it fairly soon. > > Thomas -- > > My testing of your v3 patch series for vblank timers ended up getting a > WARN_ON after about 3 days of usage. See [1]. So I don't think it's 100% > ready yet. > > But I agree we need your synthetic vblank timer support to address the > Hyper-V DRM driver performance issue, before removing the Hyper-V > fbdev driver. (See [2] for a description of the performance issue.) > > Second, isn't it customary to mark a driver as deprecated for a period > of time, before removing it entirely? I don't see any documentation > on the deprecation process, but I've seen it done in other cases. If you > grep through all the kernel Kconfig files, you'll see entries tagged with > DEPRECATED. Also the driver should be updated to output a deprecated > message when it loads. Is deprecating the driver a mandatory step? > Michael > > [1] https://lore.kernel.org/dri-devel/BN7PR02MB4148E80C13605F6EAD2B0A03D40FA@BN7PR02MB4148.namprd02.prod.outlook.com/ > [2] https://lore.kernel.org/dri-devel/SN6PR02MB415702B00D6D52B0EE962C98D46CA@SN6PR02MB4157.namprd02.prod.outlook.com/ > >> >> Best regards >> Thomas >> >>> >>> Signed-off-by: Prasanna Kumar T S M >>> --- >>> MAINTAINERS | 1 - >>> drivers/video/fbdev/Kconfig | 8 - >>> drivers/video/fbdev/Makefile | 1 - >>> drivers/video/fbdev/hyperv_fb.c | 1386 ------------------------------- >>> 4 files changed, 1396 deletions(-) >>> delete mode 100644 drivers/video/fbdev/hyperv_fb.c >>>