From patchwork Thu Apr 9 17:17:05 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Taylor, Clinton A" X-Patchwork-Id: 6189741 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 6971DBF4A6 for ; Thu, 9 Apr 2015 17:19:16 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 701CF2037B for ; Thu, 9 Apr 2015 17:19:15 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 9A6CA20376 for ; Thu, 9 Apr 2015 17:19:14 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B6AA06E811; Thu, 9 Apr 2015 10:19:13 -0700 (PDT) X-Original-To: Intel-gfx@lists.freedesktop.org Delivered-To: Intel-gfx@lists.freedesktop.org Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by gabe.freedesktop.org (Postfix) with ESMTP id 534B96E811 for ; Thu, 9 Apr 2015 10:19:12 -0700 (PDT) Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP; 09 Apr 2015 10:19:11 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.11,551,1422950400"; d="scan'208";a="677847280" Received: from cataylo2-ubuntu64-12.jf.intel.com ([134.134.145.29]) by orsmga001.jf.intel.com with ESMTP; 09 Apr 2015 10:19:11 -0700 From: clinton.a.taylor@intel.com To: Intel-gfx@lists.freedesktop.org Date: Thu, 9 Apr 2015 10:17:05 -0700 Message-Id: <1428599825-1000-1-git-send-email-clinton.a.taylor@intel.com> X-Mailer: git-send-email 1.7.9.5 Subject: [Intel-gfx] [PATCH] drm/i915/chv: Remove DPIO force latency causing interpair skew issue X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Clint Taylor Latest version of the "CHV DPIO programming notes" no longer requires writes to TX DW 11 to fix a +2UI interpair skew issue. The current code from April 2014 was actually causing additional skew issues between all TMDS pairs. Signed-off-by: Clint Taylor Tested-By: Intel Graphics QA PRTS (Patch Regression Test System Contact: shuang.he@intel.com) --- drivers/gpu/drm/i915/intel_hdmi.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c index 26222e6..3cef326 100644 --- a/drivers/gpu/drm/i915/intel_hdmi.c +++ b/drivers/gpu/drm/i915/intel_hdmi.c @@ -1515,11 +1515,6 @@ static void chv_hdmi_pre_enable(struct intel_encoder *encoder) /* Program Tx latency optimal setting */ for (i = 0; i < 4; i++) { - /* Set the latency optimal bit */ - data = (i == 1) ? 0x0 : 0x6; - vlv_dpio_write(dev_priv, pipe, CHV_TX_DW11(ch, i), - data << DPIO_FRC_LATENCY_SHFIT); - /* Set the upar bit */ data = (i == 1) ? 0x0 : 0x1; vlv_dpio_write(dev_priv, pipe, CHV_TX_DW14(ch, i),