Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753278Ab2HUGmk (ORCPT ); Tue, 21 Aug 2012 02:42:40 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:33092 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752488Ab2HUGmg (ORCPT ); Tue, 21 Aug 2012 02:42:36 -0400 MIME-Version: 1.0 X-Originating-IP: [178.83.130.250] In-Reply-To: <20120821051318.GB3625@herton-Z68MA-D2H-B3> References: <20120820035457.653002510@linuxfoundation.org> <20120820035458.292084336@linuxfoundation.org> <20120821051318.GB3625@herton-Z68MA-D2H-B3> Date: Tue, 21 Aug 2012 08:42:35 +0200 Message-ID: Subject: Re: [ 04/16] drm/i915: correctly order the ring init sequence From: Daniel Vetter To: Herton Ronaldo Krzesinski Cc: Greg Kroah-Hartman , linux-kernel@vger.kernel.org, stable@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jani Nikula , Yang Guang Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2469 Lines: 55 On Tue, Aug 21, 2012 at 7:13 AM, Herton Ronaldo Krzesinski wrote: > On Sun, Aug 19, 2012 at 08:56:03PM -0700, Greg Kroah-Hartman wrote: >> From: Greg KH >> >> 3.0-stable review patch. If anyone has any objections, please let me know. >> >> ------------------ >> >> From: Daniel Vetter >> >> commit 0d8957c8a90bbb5d34fab9a304459448a5131e06 upstream. >> >> We may only start to set up the new register values after having >> confirmed that the ring is truely off. Otherwise the hw might lose the >> newly written register values. This is caught later on in the init >> sequence, when we check whether the register writes have stuck. >> >> Reviewed-by: Jani Nikula >> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=50522 >> Tested-by: Yang Guang >> Signed-off-by: Daniel Vetter >> Signed-off-by: Greg Kroah-Hartman > [...] > > I had the same problem as on 3.2 with this change, i915 stopped working > unable to initialize render ring, eg. on one of the boots here: > [drm:init_ring_common] *ERROR* render ring initialization failed ctl 0001f003 head 00001020 tail 00000000 start 00001000 > > But unlike I was expecting as with 3.2 case, picking commit > f01db988ef6f6c70a6cc36ee71e4a98a68901229 ("drm/i915: Add wait_for in > init_ring_common") here isn't enough, it continues to fail even if I > try to increase the delay in the wait_for, I'm not sure why yet... may > be something else is going on, or 3.0 has something else missing. > > Also the same proposed patch for 3.4.10 gives the same problem, but > picking f01db988ef6f6c70a6cc36ee71e4a98a68901229 there made things work > again like happend on first 3.2.28 proposed update. Only 3.0 > is misteriously failing either way here. I guess we're missing something then still in the stable backports for 3.0. Herton, what machine do you have exaclty (lspci -nn)? Greg, I think for now it's better if you hold off on merging this patch to 3.0 until this is sorted out. Thanks, Daniel -- Daniel Vetter daniel.vetter@ffwll.ch - +41 (0) 79 365 57 48 - http://blog.ffwll.ch -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/