From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ted Percival <ted@tedp.id.au>
Subject: nouveau regression: read fault PAGE_NOT_PRESENT with new fence
 interface
Date: Thu, 18 Sep 2014 14:07:33 -0600
Message-ID: <541B3B85.6000906@tedp.id.au>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <dri-devel-bounces@lists.freedesktop.org>
Received: from amersmtp1.software.dell.com (amersmtp1.software.dell.com
 [12.106.87.226])
 by gabe.freedesktop.org (Postfix) with ESMTP id C0FAD6E13B
 for <dri-devel@lists.freedesktop.org>; Thu, 18 Sep 2014 13:22:40 -0700 (PDT)
Received: from amersmtp1.prod.quest.corp (127.0.0.1) id h3cvh00171sb for
 <dri-devel@lists.freedesktop.org>;
 Thu, 18 Sep 2014 13:07:38 -0700 (envelope-from <ted@tedp.id.au>)
List-Unsubscribe: <http://lists.freedesktop.org/mailman/options/dri-devel>,
 <mailto:dri-devel-request@lists.freedesktop.org?subject=unsubscribe>
List-Archive: <http://lists.freedesktop.org/archives/dri-devel>
List-Post: <mailto:dri-devel@lists.freedesktop.org>
List-Help: <mailto:dri-devel-request@lists.freedesktop.org?subject=help>
List-Subscribe: <http://lists.freedesktop.org/mailman/listinfo/dri-devel>,
 <mailto:dri-devel-request@lists.freedesktop.org?subject=subscribe>
Errors-To: dri-devel-bounces@lists.freedesktop.org
Sender: "dri-devel" <dri-devel-bounces@lists.freedesktop.org>
To: Maarten Lankhorst <maarten.lankhorst@ubuntu.com>
Cc: Ben Skeggs <bskeggs@redhat.com>, dri-devel@lists.freedesktop.org
List-Id: dri-devel@lists.freedesktop.org

Hi, I noticed a regression in the next-20140903 kernel that was not
present in next-20140902. When Xorg starts up, the display is garbled
(or contains old image bits) and I see a page fault in the kernel log. X
is not usable in this state - there is no pointer and gdm doesn't come
up. It works fine after Xorg (gdm3) is restarted. The fault is still
present in next-20140918.

[drm] Initialized nouveau 1.2.0 20120801 for 0000:01:00.0 on minor 0
nouveau E[   PFIFO][0000:01:00.0] read fault at 0x0001260000
[PAGE_NOT_PRESENT] from PGRAPH/GPC0/TEX on channel 0x001fcd1000 [Xorg[3874]]
nouveau E[   PFIFO][0000:01:00.0] PGRAPH engine fault on channel 2,
recovering...
nouveau E[  PGRAPH][0000:01:00.0] TRAP ch 2 [0x001fcd1000 Xorg[3874]]
nouveau E[  PGRAPH][0000:01:00.0] GPC0/TPC0/TEX: 0x80000041

My hardware is: NVIDIA Corporation GF119 [Quadro NVS 4200M] (rev a1)

I bisected it down to this commit:

  commit 29ba89b2371d466ca68973525816cf10debc2655
  Author: Maarten Lankhorst <maarten.lankhorst@ubuntu.com>
  Date:   Thu Jan 9 11:03:11 2014 +0100

      drm/nouveau: rework to new fence interface

      Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
      Acked-by: Ben Skeggs <bskeggs@redhat.com>

I tried tracing the DEVICE, PGRAPH, PFIFO & PCE0 engines but nothing
obvious stood out before the read fault shown above.

Is there any other information I can provide to help track this down?
paranoia or spam level logging, for example?