From patchwork Mon Jan 4 11:21:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Mika Kahola X-Patchwork-Id: 7947021 Return-Path: X-Original-To: patchwork-intel-gfx@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 57CE79F88A for ; Mon, 4 Jan 2016 11:20:31 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 795F620304 for ; Mon, 4 Jan 2016 11:20:30 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 888392035D for ; Mon, 4 Jan 2016 11:20:29 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id D01B86E046; Mon, 4 Jan 2016 03:20:28 -0800 (PST) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by gabe.freedesktop.org (Postfix) with ESMTP id 47FDF6E046 for ; Mon, 4 Jan 2016 03:20:27 -0800 (PST) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP; 04 Jan 2016 03:20:27 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,520,1444719600"; d="scan'208";a="883363572" Received: from sorvi.fi.intel.com ([10.237.72.161]) by orsmga002.jf.intel.com with ESMTP; 04 Jan 2016 03:20:26 -0800 From: Mika Kahola To: intel-gfx@lists.freedesktop.org Date: Mon, 4 Jan 2016 13:21:22 +0200 Message-Id: <1451906484-4659-2-git-send-email-mika.kahola@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1451906484-4659-1-git-send-email-mika.kahola@intel.com> References: <1451906484-4659-1-git-send-email-mika.kahola@intel.com> Subject: [Intel-gfx] [PATCH v5 1/3] drm/i915: Disable fast link training if DP config changes 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, 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 Disable DP link training optimization if DP link configuration changes. If one of the DP link parameters i.e. link rate or lane count changes the link training does no longer apply the previously computed drive current and pre-emphasis level. Instead, the link training is started with zero values. v5: Commit message update. Split the original patch in two. This part considers only changes on link configuration. Removed unnecessary debug messages. (Ville) v4: Parameter and debug message naming improvements. Fix for link parameter check (Ville) v3: Remove cached old link parameters. Instead, disable fast link training feature when link parameters are set (Ville) v2: Readout DPCD register to check if no aux handshaking is required in link training (Ander) Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91393 Signed-off-by: Mika Kahola Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/intel_dp.c | 5 +++++ drivers/gpu/drm/i915/intel_dp_link_training.c | 3 +++ 2 files changed, 8 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 796e3d3..6b36d82 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -1676,6 +1676,11 @@ found: void intel_dp_set_link_params(struct intel_dp *intel_dp, const struct intel_crtc_state *pipe_config) { + if (intel_dp->link_rate != pipe_config->port_clock || + intel_dp->lane_count != pipe_config->lane_count) { + intel_dp->train_set_valid = false; + } + intel_dp->link_rate = pipe_config->port_clock; intel_dp->lane_count = pipe_config->lane_count; } diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c index 8888793..59d59be 100644 --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -85,6 +85,9 @@ static bool intel_dp_reset_link_train(struct intel_dp *intel_dp, uint8_t dp_train_pat) { + DRM_DEBUG_KMS("link training optimization: %s\n", + intel_dp->train_set_valid ? "true" : "false"); + if (!intel_dp->train_set_valid) memset(intel_dp->train_set, 0, sizeof(intel_dp->train_set)); intel_dp_set_signal_levels(intel_dp);