From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756204AbcBIJcV (ORCPT ); Tue, 9 Feb 2016 04:32:21 -0500 Received: from mail-wm0-f49.google.com ([74.125.82.49]:33340 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751734AbcBIJcS (ORCPT ); Tue, 9 Feb 2016 04:32:18 -0500 Date: Tue, 9 Feb 2016 10:32:40 +0100 From: Daniel Vetter To: Michel =?iso-8859-1?Q?D=E4nzer?= Cc: Peter Hurley , Archit Taneja , Daniel Vetter , Ben Skeggs , Linux kernel , "dri-devel@lists.freedesktop.org" Subject: Re: BUG caused by "Use new drm_fb_helper functions" series Message-ID: <20160209093240.GF11240@phenom.ffwll.local> Mail-Followup-To: Michel =?iso-8859-1?Q?D=E4nzer?= , Peter Hurley , Archit Taneja , Ben Skeggs , Linux kernel , "dri-devel@lists.freedesktop.org" References: <56AFC1F1.5080507@hurleysoftware.com> <56B03CB4.8020503@codeaurora.org> <56B0F7B3.3020704@hurleysoftware.com> <56B1C8CE.1090607@daenzer.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <56B1C8CE.1090607@daenzer.net> X-Operating-System: Linux phenom 4.3.0-1-amd64 User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 03, 2016 at 06:30:54PM +0900, Michel Dänzer wrote: > 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. Yup. We've had patches for i915, resulted in half of mesa+glamour in-kernel, which is just pointless. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch