From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753907Ab1AXTNa (ORCPT ); Mon, 24 Jan 2011 14:13:30 -0500 Received: from mga09.intel.com ([134.134.136.24]:30174 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752754Ab1AXTN3 (ORCPT ); Mon, 24 Jan 2011 14:13:29 -0500 Message-Id: <0d30dc$krk6f6@orsmga001.jf.intel.com> X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.60,371,1291622400"; d="scan'208";a="700062216" Date: Mon, 24 Jan 2011 19:13:25 +0000 To: Knut Petersen , linux-kernel@vger.kernel.org Subject: Re: [BUG/REGRESSION] DRM / i915 / 2.6.37 and 2.6.38-rc*: DVI output gets disabled/reenabled under load Cc: jesse.barnes@intel.com References: <4D3DC997.5040605@t-online.de> From: Chris Wilson In-Reply-To: <4D3DC997.5040605@t-online.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 24 Jan 2011 19:48:55 +0100, Knut Petersen wrote: > On an AOpen i915GMm-HFS I see the following problem: > The LCD panel connected to DVI-1 gets disabled and then reenabled > under high system load (e.g. -j 15 kernel compile) if I am working on the > framebuffer console (no problems in X). DVI detection is essentially retrieving the EDID by bitbanging on the DDC. This is timing sensitive and I suspect that is being interrupted by the system activity causing the EDID data to be returned corrupted. Is that supported by any warnings in dmesg? Does increasing the drm.debug level to 0x6 reveal any more significant information? Not sure how using the unaccelerated fbcon ties in just yet. It's an extra source of latency vs X, but I would expect to impact upon DVI detection. You can simply disable the polling with 'echo n > /sys/module/drm_kms_helper/parameter/poll' -Chris -- Chris Wilson, Intel Open Source Technology Centre