Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932260AbbHXDem (ORCPT ); Sun, 23 Aug 2015 23:34:42 -0400 Received: from ferdi.naasa.net ([87.106.227.76]:49763 "EHLO ferdi.naasa.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753788AbbHXDel (ORCPT ); Sun, 23 Aug 2015 23:34:41 -0400 X-Greylist: delayed 535 seconds by postgrey-1.27 at vger.kernel.org; Sun, 23 Aug 2015 23:34:40 EDT From: Joerg Platte Subject: drm/radeon: take the mode_config mutex when dealing with hpds (v2) crashes To: alexander.deucher@amd.com, linux-kernel@vger.kernel.org Message-ID: <55DA8EB7.9000206@naasa.net> Date: Mon, 24 Aug 2015 05:25:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.0.1 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2185 Lines: 60 Dear Alex, on my old P4 based non-SMP router your patch (commit 32d12fc20e3c726ca858d0e5055fb596fce2f8bc in linux stable) crashes on Linux 4.1.4 and above. I was only able to take a picture of the whole trace https://ferdi.naasa.net/url/jplatte/IMG_3116.JPG Reverting the patch resolves the issue. This is my old graphics hardware: 01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV100 [Radeon 7000 / Radeon VE] Just for the reference, here is the full patch: commit 32d12fc20e3c726ca858d0e5055fb596fce2f8bc Author: Alex Deucher Date: Fri May 15 11:48:52 2015 -0400 drm/radeon: take the mode_config mutex when dealing with hpds (v2) commit 39fa10f7e21574a70cecf1fed0f9b36535aa68a0 upstream. Since we are messing with state in the worker. v2: drop the changes in the mst worker Signed-off-by: Alex Deucher Signed-off-by: Greg Kroah-Hartman diff --git a/drivers/gpu/drm/radeon/radeon_irq_kms.c b/drivers/gpu/drm/radeon/radeon_irq_kms.c index 7162c93..f682e53 100644 --- a/drivers/gpu/drm/radeon/radeon_irq_kms.c +++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c @@ -79,10 +79,12 @@ static void radeon_hotplug_work_func(struct work_struct *work) struct drm_mode_config *mode_config = &dev->mode_config; struct drm_connector *connector; + mutex_lock(&mode_config->mutex); if (mode_config->num_connector) { list_for_each_entry(connector, &mode_config->connector_list, head) radeon_connector_hotplug(connector); } + mutex_unlock(&mode_config->mutex); /* Just fire off a uevent and let userspace tell us what to do */ drm_helper_hpd_irq_event(dev); } Is it possible that the mutex is not defined on non-SMP systems? Can you help to resolve this regression? Best regards, Joerg -- 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/