From patchwork Thu Mar 2 08:36:03 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: 9599681 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 F2F6260453 for ; Thu, 2 Mar 2017 08:08:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E18B5283A6 for ; Thu, 2 Mar 2017 08:08:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D498F2846A; Thu, 2 Mar 2017 08:08:55 +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 474C7283A6 for ; Thu, 2 Mar 2017 08:08:55 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id A35E46EA7F; Thu, 2 Mar 2017 08:08:54 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by gabe.freedesktop.org (Postfix) with ESMTPS id 3287C6EA7F for ; Thu, 2 Mar 2017 08:08:54 +0000 (UTC) Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Mar 2017 00:08:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.35,230,1484035200"; d="scan'208";a="71294011" Received: from shawnle1-cm6330-cm6630-cm6730-cm6830-m11aa-8.itwn.intel.com ([10.5.230.140]) by fmsmga005.fm.intel.com with ESMTP; 02 Mar 2017 00:08:41 -0800 From: "Lee, Shawn C" To: intel-gfx@lists.freedesktop.org Date: Thu, 2 Mar 2017 16:36:03 +0800 Message-Id: <1488443763-26709-1-git-send-email-shawn.c.lee@intel.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1488443447-26655-1-git-send-email-shawn.c.lee@intel.com> References: <1488443447-26655-1-git-send-email-shawn.c.lee@intel.com> Cc: Jani Nikula , Cooper Chiou , Wei Shun Chen Subject: [Intel-gfx] [PATCH v2] drm/i915/dp: 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. 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: Wei Shun Chen Cc: Gary C Wang Cc: Jani Nikula Signed-off-by: Lee, Shawn C --- drivers/gpu/drm/i915/intel_dp.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index 024798a9c016..f6229d616971 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -4225,6 +4225,7 @@ 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); + struct drm_i915_private *dev_priv = dev->dev_private; u8 link_status[DP_LINK_STATUS_SIZE]; WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex)); @@ -4247,6 +4248,27 @@ static void intel_dp_handle_test_request(struct intel_dp *intel_dp) /* Retrain if Channel EQ or CR not ok */ if (!drm_dp_channel_eq_ok(link_status, intel_dp->lane_count)) { + if (is_edp(intel_dp) && dev_priv->psr.enabled) { + u8 retry; + + for (retry = 0; retry < 3; retry++) { + /* + * EQ not ok may caused by fast link train while exit PSR active, + * wait at least 1000 us then read it again. + */ + DRM_DEBUG_KMS("%s: channel EQ not ok, retry = %d, DPCD 0x202 = 0x%x, 0x203 = 0x%x, 0x204 = 0x%x\n", + intel_encoder->base.name, retry, link_status[0], link_status[1], link_status[2]); + usleep_range(1000, 1500); + if (!intel_dp_get_link_status(intel_dp, link_status)) { + DRM_ERROR("Failed to get link status\n"); + return; + } + + if (drm_dp_channel_eq_ok(link_status, intel_dp->lane_count)) + return; + } + } + DRM_DEBUG_KMS("%s: channel EQ not ok, retraining\n", intel_encoder->base.name);