From patchwork Wed Sep 12 22:57:16 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Navare, Manasi" X-Patchwork-Id: 10598429 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 46FD6112B for ; Wed, 12 Sep 2018 22:55:19 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 34F3C2AC76 for ; Wed, 12 Sep 2018 22:55:19 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 295F02AC7B; Wed, 12 Sep 2018 22:55:19 +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=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=ham 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 D3B1F2AC76 for ; Wed, 12 Sep 2018 22:55:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 51D186E50A; Wed, 12 Sep 2018 22:55:13 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9F03D6E4B7 for ; Wed, 12 Sep 2018 22:55:11 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Sep 2018 15:55:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.53,366,1531810800"; d="scan'208";a="85487929" Received: from labuser-z97x-ud5h.jf.intel.com ([10.54.75.151]) by fmsmga002.fm.intel.com with ESMTP; 12 Sep 2018 15:55:09 -0700 From: Manasi Navare To: intel-gfx@lists.freedesktop.org Date: Wed, 12 Sep 2018 15:57:16 -0700 Message-Id: <20180912225719.17574-1-manasi.d.navare@intel.com> X-Mailer: git-send-email 2.18.0 Subject: [Intel-gfx] [PATCH v2 1/4] drm/i915/dp: Link train Fallback on eDP only if fallback link BW can fit panel's native mode X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Daniel Vetter , Lucas De Marchi MIME-Version: 1.0 Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP This patch fixes the original commit c0cfb10d9e1de49 ("drm/i915/edp: Do not do link training fallback or prune modes on EDP") that causes a blank screen in case of certain eDP panels (Eg: seen on Dell XPS13 9350) where first link training fails and a retraining is required by falling back to lower link rate/lane count. In case of some panels they advertise higher link rate/lane count than whats required for supporting the panel's native mode. But we always link train at highest link rate/lane count for eDP and if that fails we can still fallback to lower link rate/lane count as long as the fallback link BW still fits the native mode to avoid pruning the panel's native mode yet retraining at fallback values to recover from a blank screen. v2: * Send uevent if link failure on eDP unconditionally Cc: Clinton Taylor Cc: Jani Nikula Cc: Ville Syrjala Cc: Daniel Vetter Cc: Lucas De Marchi Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107489 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=105338 Signed-off-by: Manasi Navare Tested-by: Alexander Wilson Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/intel_dp.c | 29 +++++++++++++++++++ drivers/gpu/drm/i915/intel_dp_link_training.c | 26 ++++++----------- 2 files changed, 38 insertions(+), 17 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 436c22de33b6..e4de5257cd87 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -557,6 +557,21 @@ static bool intel_dp_link_params_valid(struct intel_dp *intel_dp, int link_rate, return true; } +static bool intel_dp_can_link_train_fallback_for_edp(struct intel_dp *intel_dp, + int link_rate, + uint8_t lane_count) +{ + struct drm_display_mode *fixed_mode = intel_dp->attached_connector->panel.fixed_mode; + int mode_rate, max_rate; + + mode_rate = intel_dp_link_required(fixed_mode->clock, 18); + max_rate = intel_dp_max_data_rate(link_rate, lane_count); + if (mode_rate > max_rate) + return false; + + return true; +} + int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, int link_rate, uint8_t lane_count) { @@ -566,9 +581,23 @@ int intel_dp_get_link_train_fallback_values(struct intel_dp *intel_dp, intel_dp->num_common_rates, link_rate); if (index > 0) { + if (intel_dp_is_edp(intel_dp) && + !intel_dp_can_link_train_fallback_for_edp(intel_dp, + intel_dp->common_rates[index - 1], + lane_count)) { + DRM_DEBUG_KMS("Retrying Link training for eDP with same parameters\n"); + return 0; + } intel_dp->max_link_rate = intel_dp->common_rates[index - 1]; intel_dp->max_link_lane_count = lane_count; } else if (lane_count > 1) { + if (intel_dp_is_edp(intel_dp) && + !intel_dp_can_link_train_fallback_for_edp(intel_dp, + intel_dp_max_common_rate(intel_dp), + lane_count >> 1)) { + DRM_DEBUG_KMS("Retrying Link training for eDP with same parameters\n"); + return 0; + } intel_dp->max_link_rate = intel_dp_max_common_rate(intel_dp); intel_dp->max_link_lane_count = lane_count >> 1; } else { diff --git a/drivers/gpu/drm/i915/intel_dp_link_training.c b/drivers/gpu/drm/i915/intel_dp_link_training.c index a9f40985a621..30be0e39bd5f 100644 --- a/drivers/gpu/drm/i915/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/intel_dp_link_training.c @@ -367,22 +367,14 @@ intel_dp_start_link_train(struct intel_dp *intel_dp) return; failure_handling: - /* Dont fallback and prune modes if its eDP */ - if (!intel_dp_is_edp(intel_dp)) { - DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d", - intel_connector->base.base.id, - intel_connector->base.name, - intel_dp->link_rate, intel_dp->lane_count); - if (!intel_dp_get_link_train_fallback_values(intel_dp, - intel_dp->link_rate, - intel_dp->lane_count)) - /* Schedule a Hotplug Uevent to userspace to start modeset */ - schedule_work(&intel_connector->modeset_retry_work); - } else { - DRM_ERROR("[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d", - intel_connector->base.base.id, - intel_connector->base.name, - intel_dp->link_rate, intel_dp->lane_count); - } + DRM_DEBUG_KMS("[CONNECTOR:%d:%s] Link Training failed at link rate = %d, lane count = %d", + intel_connector->base.base.id, + intel_connector->base.name, + intel_dp->link_rate, intel_dp->lane_count); + if (!intel_dp_get_link_train_fallback_values(intel_dp, + intel_dp->link_rate, + intel_dp->lane_count)) + /* Schedule a Hotplug Uevent to userspace to start modeset */ + schedule_work(&intel_connector->modeset_retry_work); return; }