From patchwork Tue Jan 5 13:50:01 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mika Kahola X-Patchwork-Id: 7955071 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 A0683BEEED for ; Tue, 5 Jan 2016 13:49:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D0EDA20383 for ; Tue, 5 Jan 2016 13:49:19 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id 03C3C2020F for ; Tue, 5 Jan 2016 13:49:19 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 710F46E55E; Tue, 5 Jan 2016 05:49:18 -0800 (PST) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by gabe.freedesktop.org (Postfix) with ESMTP id BA82A6E55C for ; Tue, 5 Jan 2016 05:49:15 -0800 (PST) Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga103.jf.intel.com with ESMTP; 05 Jan 2016 05:49:05 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.20,525,1444719600"; d="scan'208";a="874962214" Received: from sorvi.fi.intel.com ([10.237.72.161]) by fmsmga001.fm.intel.com with ESMTP; 05 Jan 2016 05:49:03 -0800 From: Mika Kahola To: intel-gfx@lists.freedesktop.org Date: Tue, 5 Jan 2016 15:50:01 +0200 Message-Id: <1452001802-9449-3-git-send-email-mika.kahola@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1452001802-9449-1-git-send-email-mika.kahola@intel.com> References: <1452001802-9449-1-git-send-email-mika.kahola@intel.com> Cc: thierry.reding@gmail.com Subject: [Intel-gfx] [PATCH v6 2/3] drm/i915: Check DP no aux transaction bit on link training 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 Check if *NO_AUX_TRANSACTIONS_LINK_TRAINING* bit is set on DPCD registers. If this bit is set, we can reuse the known good drive current and pre-emphasis level from the last "full" link training. v2: Commit message update (Thierry) Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=91393 Signed-off-by: Mika Kahola --- drivers/gpu/drm/i915/intel_dp.c | 2 +- drivers/gpu/drm/i915/intel_dp_link_training.c | 19 +++++++++++++++++++ drivers/gpu/drm/i915/intel_drv.h | 1 + 3 files changed, 21 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 6b36d82..3137187 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3852,7 +3852,7 @@ intel_dp_link_down(struct intel_dp *intel_dp) intel_dp->DP = DP; } -static bool +bool intel_dp_get_dpcd(struct intel_dp *intel_dp) { struct intel_digital_port *dig_port = dp_to_dig_port(intel_dp); diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c index 8f22c92..bcf2801 100644 --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -85,6 +85,25 @@ static bool intel_dp_reset_link_train(struct intel_dp *intel_dp, uint8_t dp_train_pat) { + bool has_dpcd; + bool no_aux_handshake = false; + + has_dpcd = intel_dp_get_dpcd(intel_dp); + + /* + * Source device can try to use drive current and pre-emphasis + * parameters computed by the last "full" link training if the + * DP_NO_AUX_HANDSHAKE_LINK_TRAINING bit is set to 1. + */ + if (has_dpcd) { + if (intel_dp->dpcd[DP_DPCD_REV] >= 0x11) { + no_aux_handshake = (intel_dp->dpcd[DP_MAX_DOWNSPREAD] & + DP_NO_AUX_HANDSHAKE_LINK_TRAINING); + } + } + + intel_dp->train_set_valid &= no_aux_handshake; + DRM_DEBUG_KMS("link training optimization: %s\n", yesno(intel_dp->train_set_valid)); diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 0438b57..918bdf1 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -1250,6 +1250,7 @@ int intel_dp_sink_crc(struct intel_dp *intel_dp, u8 *crc); bool intel_dp_compute_config(struct intel_encoder *encoder, struct intel_crtc_state *pipe_config); bool intel_dp_is_edp(struct drm_device *dev, enum port port); +bool intel_dp_get_dpcd(struct intel_dp *intel_dp); enum irqreturn intel_dp_hpd_pulse(struct intel_digital_port *intel_dig_port, bool long_hpd); void intel_edp_backlight_on(struct intel_dp *intel_dp);