From patchwork Tue Oct 9 09:18:13 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Kuoppala X-Patchwork-Id: 1569541 Return-Path: X-Original-To: patchwork-dri-devel@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by patchwork2.kernel.org (Postfix) with ESMTP id 49FE9DFFAD for ; Tue, 9 Oct 2012 11:06:59 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 686509EB76 for ; Tue, 9 Oct 2012 04:06:59 -0700 (PDT) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga03.intel.com (mga03.intel.com [143.182.124.21]) by gabe.freedesktop.org (Postfix) with ESMTP id 043819E747 for ; Tue, 9 Oct 2012 02:18:14 -0700 (PDT) Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga101.ch.intel.com with ESMTP; 09 Oct 2012 02:18:14 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,560,1344236400"; d="scan'208";a="202249477" Received: from rosetta.fi.intel.com (HELO rosetta) ([10.237.72.92]) by azsmga001.ch.intel.com with ESMTP; 09 Oct 2012 02:18:12 -0700 Received: by rosetta (Postfix, from userid 1000) id 0B136641D0A; Tue, 9 Oct 2012 12:18:21 +0300 (EEST) From: mika.kuoppala@intel.com To: paulepanter@users.sourceforge.net Subject: [PATCH v2] Documentation: kernel-parameters.txt Add drm_kms_helper.poll Date: Tue, 9 Oct 2012 12:18:13 +0300 Message-Id: <1349774293-27285-1-git-send-email-mika.kuoppala@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: References: X-Mailman-Approved-At: Tue, 09 Oct 2012 04:06:21 -0700 Cc: dri-devel@lists.freedesktop.org, Mika Kuoppala X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org Errors-To: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org From: Mika Kuoppala Possibility to disable polling to find connected displays was introduced by commit [1]: commit e58f637bb96d5a0ae0919b9998b891d1ba7e47c9 Author: Chris Wilson Date: Fri Aug 20 09:13:36 2010 +0100 drm/kms: Add a module parameter to disable polling Add description for this parameter to kernel-parameters.txt [1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=e58f637bb96d5a0ae0919b9998b891d1ba7e47c9 Signed-off-by: Mika Kuoppala --- Documentation/kernel-parameters.txt | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index f777fa9..0f0f071 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -741,6 +741,22 @@ bytes respectively. Such letter suffixes can also be entirely omitted. if its name and a colon are prepended to the EDID name. + drm_kms_helper.poll= + Polling for connected display devices on older systems + without Hot Plug Detect (HPD) support, can be quite + expensive. Poll will happen periodically and can in + worst cases take several hundred milliseconds, + depending on the hardware. This will cause visible + stalls, for example in video playback. These stalls + might happen even when your video is on HDP output + but you have other non HDP outputs in your hw + configuration. If you experience stalls in display + output occurring every 10 seconds, disabling polling + might help. With polling disabled you need to manually + use xrandr to trigger detection. + Format: (1/Y/y=enable, 0/N/n=disable) + default: enabled + dscc4.setup= [NET] dyndbg[="val"] [KNL,DYNAMIC_DEBUG]