From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753078AbcBCJbH (ORCPT ); Wed, 3 Feb 2016 04:31:07 -0500 Received: from darkcity.gna.ch ([195.226.6.51]:50708 "EHLO mail.gna.ch" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751533AbcBCJbF (ORCPT ); Wed, 3 Feb 2016 04:31:05 -0500 Subject: Re: BUG caused by "Use new drm_fb_helper functions" series To: Peter Hurley , Archit Taneja , Daniel Vetter , Ben Skeggs References: <56AFC1F1.5080507@hurleysoftware.com> <56B03CB4.8020503@codeaurora.org> <56B0F7B3.3020704@hurleysoftware.com> Cc: Linux kernel , "dri-devel@lists.freedesktop.org" From: =?UTF-8?Q?Michel_D=c3=a4nzer?= X-Enigmail-Draft-Status: N1110 Message-ID: <56B1C8CE.1090607@daenzer.net> Date: Wed, 3 Feb 2016 18:30:54 +0900 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.5.0 MIME-Version: 1.0 In-Reply-To: <56B0F7B3.3020704@hurleysoftware.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03.02.2016 03:38, Peter Hurley wrote: > On 02/01/2016 09:20 PM, Archit Taneja wrote: >> Hi Peter, >> >> On 02/02/2016 02:07 AM, Peter Hurley wrote: >>> Hi Archit, >>> >>> Just booting 4.4-rc5+, I got this splat [1] >>> At first glance, this appears to be a simple fix. >> >> Thanks for sharing this. >> >>> >>> However, I'm concerned that fbcon functions, which may be called with >>> interrupts disabled, are now hooked up to fbdev functions which may assume >>> interrupts are not disabled (as is the case with cfb_imageblit()). >> >> In the case when CONFIG_FB is enabled, drm_fb_helper_cfb_imageblit >> helper simply wraps around cfg_imageblit, so I don't see how we'd have >> any difference in behaviour. > > > Sorry; terrible attribution on my part. > This bug clearly has nothing to do with this series. > > But a better look has me wondering how all these gpus are syncing > the framebuffer for direct access via cfb_imageblit and friends. I only see > nouveau and intel gma even trying. Probably no other DRM driver uses hardware acceleration for fbcon. -- Earthling Michel Dänzer | http://www.amd.com Libre software enthusiast | Mesa and X developer