From patchwork Tue Apr 25 10:09:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Lee, Shawn C" X-Patchwork-Id: 9697789 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 4F5C8601D3 for ; Tue, 25 Apr 2017 09:39:50 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 474202845C for ; Tue, 25 Apr 2017 09:39:50 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3A6DC284E5; Tue, 25 Apr 2017 09:39:50 +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=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 9AE302843B for ; Tue, 25 Apr 2017 09:39:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 351D889C6A; Tue, 25 Apr 2017 09:39:48 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8E71F89C6A for ; Tue, 25 Apr 2017 09:39:46 +0000 (UTC) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga104.jf.intel.com with ESMTP; 25 Apr 2017 02:39:45 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.37,249,1488873600"; d="scan'208";a="849541696" Received: from shawnle1-cm6330-cm6630-cm6730-cm6830-m11aa-8.itwn.intel.com ([10.5.230.22]) by FMSMGA003.fm.intel.com with ESMTP; 25 Apr 2017 02:39:44 -0700 From: "Lee, Shawn C" To: intel-gfx@lists.freedesktop.org Date: Tue, 25 Apr 2017 18:09:01 +0800 Message-Id: <1493114941-6889-1-git-send-email-shawn.c.lee@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1488443763-26709-1-git-send-email-shawn.c.lee@intel.com> References: <1488443763-26709-1-git-send-email-shawn.c.lee@intel.com> Cc: Cooper Chiou , Jim Bride , Jani Nikula , Rodrigo Vivi Subject: [Intel-gfx] [PATCH v4] drm/i915/edp: Read link status more times when EQ not done 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-Virus-Scanned: ClamAV using ClamSMTP From: "Lee, Shawn C" Display driver read DPCD register 0x202, 0x203 and 0x204 to identify eDP sink status.If PSR exit is ongoing at eDP sink, and eDP source read these registers at the same time. Panel will report EQ & symbol lock not done. It will cause panel display flicking. Try to read link status more times if eDP EQ not done. Panel side request at least 1000us for fast link train while doing PSR exit. So wait more than 1000us then retrieve sink's status again. Change log: v2: - modify this mechanism just used for eDP + PSR enabled. v3: - move the intel_dp_get_link_status() call closer to the drm_dp_channel_eq_ok() v4: - Rebase / minor typo fix. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99639 TEST=Reboot DUT and no flicking on local display at login screen Cc: Cooper Chiou Cc: Gary C Wang Cc: Jani Nikula Cc: Rodrigo Vivi Cc: Jim Bride Signed-off-by: Shawn Lee --- drivers/gpu/drm/i915/intel_dp.c | 36 +++++++++++++++++++++++++----------- 1 file changed, 25 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 08834f74d396..7d2b68c538cf 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4256,15 +4256,11 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp) { struct intel_encoder *intel_encoder = &dp_to_dig_port(intel_dp)->base; struct drm_device *dev = intel_dp_to_dev(intel_dp); - u8 link_status[DP_LINK_STATUS_SIZE]; + struct drm_i915_private *dev_priv = dev->dev_private; + u8 link_status[DP_LINK_STATUS_SIZE], retry = 1; WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); - if (!intel_dp_get_link_status(intel_dp, link_status)) { - DRM_ERROR("Failed to get link status\n"); - return; - } - if (!intel_encoder->base.crtc) return; @@ -4278,13 +4274,31 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp) if (!intel_dp_link_params_valid(intel_dp)) return; - /* Retrain if Channel EQ or CR not ok */ - if (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count)) { - DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n", - intel_encoder->base.name); + if (is_edp(intel_dp) && dev_priv->psr.enabled) + retry = 3; + + while (retry--) { + if (!intel_dp_get_link_status(intel_dp, link_status)) { + DRM_ERROR("Failed to get link status\n"); + return; + } - intel_dp_retrain_link(intel_dp); + if (drm_dp_channel_eq_ok(link_status, intel_dp->lane_count)) + return; + + /* + * EQ not ok may caused by fast link train while exit PSR active, + * wait at least 1000 us then read it again. + */ + if (retry) + usleep_range(1000, 1500); } + + /* Retrain if Channel EQ or CR not ok */ + DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n", + intel_encoder->base.name); + + intel_dp_retrain_link(intel_dp); } /*