From patchwork Tue Nov 15 03:13:22 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Navare, Manasi" X-Patchwork-Id: 9428865 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 3E78660484 for ; Tue, 15 Nov 2016 03:12:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2D2D328B19 for ; Tue, 15 Nov 2016 03:12:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2261C28B39; Tue, 15 Nov 2016 03:12:21 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A6ABD28B19 for ; Tue, 15 Nov 2016 03:12:20 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 555186E55D; Tue, 15 Nov 2016 03:12:02 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by gabe.freedesktop.org (Postfix) with ESMTPS id 762246E535; Tue, 15 Nov 2016 03:11:49 +0000 (UTC) Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP; 14 Nov 2016 19:11:43 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,640,1473145200"; d="scan'208";a="31046749" Received: from manasi-otcmedia.jf.intel.com ([10.7.199.175]) by orsmga004.jf.intel.com with ESMTP; 14 Nov 2016 19:11:43 -0800 From: Manasi Navare To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH 4/5] drm/i915: Find fallback link rate/lane count Date: Mon, 14 Nov 2016 19:13:22 -0800 Message-Id: <1479179603-28476-5-git-send-email-manasi.d.navare@intel.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1479179603-28476-1-git-send-email-manasi.d.navare@intel.com> References: <1479179603-28476-1-git-send-email-manasi.d.navare@intel.com> Cc: Manasi Navare , Daniel Vetter X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP If link training fails, then we need to fallback to lower link rate first and if link training fails at RBR, then fallback to lower lane count. This function finds the next lower link rate/lane count value after link training failure. v2: Squash the patch that returns the link rate index (Jani Nikula) Acked-by: Tony Cheng Acked-by: Harry Wentland Cc: Ville Syrjala Cc: Jani Nikula Cc: Daniel Vetter Signed-off-by: Manasi Navare --- drivers/gpu/drm/i915/intel_dp.c | 42 ++++++++++++++++++++++++++++++++++++++++ drivers/gpu/drm/i915/intel_drv.h | 6 ++++++ 2 files changed, 48 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index a1b0181..e87b451 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -288,6 +288,48 @@ static int intel_dp_common_rates(struct intel_dp *intel_dp, common_rates); } +static int intel_dp_link_rate_index(struct intel_dp *intel_dp, + int *common_rates, int link_rate) +{ + int common_len; + int index; + + common_len = intel_dp_common_rates(intel_dp, common_rates); + for (index = 0; index < common_len; index++) { + if (link_rate == common_rates[common_len - index - 1]) + return common_len - index - 1; + } + + return -1; +} + +int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, + int link_rate, uint8_t lane_count) +{ + int common_rates[DP_MAX_SUPPORTED_RATES] = {}; + int common_len; + int link_rate_index = -1; + + common_len = intel_dp_common_rates(intel_dp, common_rates); + link_rate_index = intel_dp_link_rate_index(intel_dp, + common_rates, + link_rate); + if (link_rate_index > 0) { + intel_dp->fallback_link_rate_index = link_rate_index - 1; + intel_dp->fallback_link_rate = common_rates[intel_dp->fallback_link_rate_index]; + intel_dp->fallback_lane_count = intel_dp_max_lane_count(intel_dp); + } else if (lane_count > 1) { + intel_dp->fallback_link_rate_index = common_len - 1; + intel_dp->fallback_link_rate = common_rates[intel_dp->fallback_link_rate_index]; + intel_dp->fallback_lane_count = lane_count >> 1; + } else { + DRM_ERROR("Link Training Unsuccessful\n"); + return -1; + } + + return 0; +} + static enum drm_mode_status intel_dp_mode_valid(struct drm_connector *connector, struct drm_display_mode *mode) diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h index 75252ec..55ceb44 100644 --- a/drivers/gpu/drm/i915/intel_drv.h +++ b/drivers/gpu/drm/i915/intel_drv.h @@ -887,6 +887,10 @@ struct intel_dp { uint32_t DP; int link_rate; uint8_t lane_count; + int fallback_link_rate; + uint8_t fallback_lane_count; + int fallback_link_rate_index; + bool link_train_failed; uint8_t sink_count; bool link_mst; bool has_audio; @@ -1383,6 +1387,8 @@ bool intel_dp_init_connector(struct intel_digital_port *intel_dig_port, void intel_dp_set_link_params(struct intel_dp *intel_dp, int link_rate, uint8_t lane_count, bool link_mst); +int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, + int link_rate, uint8_t lane_count); void intel_dp_start_link_train(struct intel_dp *intel_dp); void intel_dp_stop_link_train(struct intel_dp *intel_dp); void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode);