From patchwork Wed Mar 17 19:01:49 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Imre Deak X-Patchwork-Id: 404712 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 01DA6C433E9 for ; Wed, 17 Mar 2021 19:03:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B183C64F6E for ; Wed, 17 Mar 2021 19:03:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233069AbhCQTCd (ORCPT ); Wed, 17 Mar 2021 15:02:33 -0400 Received: from mga09.intel.com ([134.134.136.24]:43718 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232968AbhCQTCU (ORCPT ); Wed, 17 Mar 2021 15:02:20 -0400 IronPort-SDR: eiDKl//GgWAFOdjdgRfi04QkvRBr4zeVS66W8nOO4P3ui3xz5UF0Tnv2cptdIFfHPMIwLn9Ydv n43W95F4u1hQ== X-IronPort-AV: E=McAfee;i="6000,8403,9926"; a="189621351" X-IronPort-AV: E=Sophos;i="5.81,257,1610438400"; d="scan'208";a="189621351" Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2021 12:01:55 -0700 IronPort-SDR: cjFMaNIuTxTUnEqiJJDha5Qfb1+OSoFk5REtfhFhiuWIBggfxCvwxUCu2ZQVQou7RZF74VCaqS FtRXc4aEyaIQ== X-IronPort-AV: E=Sophos;i="5.81,257,1610438400"; d="scan'208";a="450205782" Received: from ideak-desk.fi.intel.com ([10.237.68.141]) by orsmga001-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Mar 2021 12:01:51 -0700 From: Imre Deak To: intel-gfx@lists.freedesktop.org Cc: stable@vger.kernel.org, =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= Subject: [PATCH v2 2/3] drm/i915: Disable LTTPR support when the DPCD rev < 1.4 Date: Wed, 17 Mar 2021 21:01:49 +0200 Message-Id: <20210317190149.4032966-1-imre.deak@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210317184901.4029798-3-imre.deak@intel.com> References: <20210317184901.4029798-3-imre.deak@intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org By the specification the 0xF0000-0xF02FF range is only valid when the DPCD revision is 1.4 or higher. Disable LTTPR support if this isn't so. Trying to detect LTTPRs returned corrupted values for the above DPCD range at least on a Skylake host with an LG 43UD79-B monitor with a DPCD revision 1.2 connected. v2: Add the actual version check. Fixes: 7b2a4ab8b0ef ("drm/i915: Switch to LTTPR transparent mode link training") Cc: # v5.11 Cc: Ville Syrjälä Signed-off-by: Imre Deak Reviewed-by: Ville Syrjälä --- drivers/gpu/drm/i915/display/intel_dp.c | 4 +- .../drm/i915/display/intel_dp_link_training.c | 48 ++++++++++++++----- .../drm/i915/display/intel_dp_link_training.h | 2 +- 3 files changed, 39 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index b6b5776f5a66..873684da0cd4 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -3711,9 +3711,7 @@ intel_dp_get_dpcd(struct intel_dp *intel_dp) { int ret; - intel_dp_lttpr_init(intel_dp); - - if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd)) + if (intel_dp_init_lttpr_and_dprx_caps(intel_dp) < 0) return false; /* diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.c b/drivers/gpu/drm/i915/display/intel_dp_link_training.c index c0e25c75c105..5a821d644e9c 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.c +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.c @@ -35,6 +35,11 @@ intel_dp_dump_link_status(struct drm_device *drm, link_status[3], link_status[4], link_status[5]); } +static void intel_dp_reset_lttpr_common_caps(struct intel_dp *intel_dp) +{ + memset(&intel_dp->lttpr_common_caps, 0, sizeof(intel_dp->lttpr_common_caps)); +} + static void intel_dp_reset_lttpr_count(struct intel_dp *intel_dp) { intel_dp->lttpr_common_caps[DP_PHY_REPEATER_CNT - @@ -96,8 +101,7 @@ static bool intel_dp_read_lttpr_common_caps(struct intel_dp *intel_dp) if (drm_dp_read_lttpr_common_caps(&intel_dp->aux, intel_dp->lttpr_common_caps) < 0) { - memset(intel_dp->lttpr_common_caps, 0, - sizeof(intel_dp->lttpr_common_caps)); + intel_dp_reset_lttpr_common_caps(intel_dp); return false; } @@ -119,30 +123,49 @@ intel_dp_set_lttpr_transparent_mode(struct intel_dp *intel_dp, bool enable) } /** - * intel_dp_lttpr_init - detect LTTPRs and init the LTTPR link training mode + * intel_dp_init_lttpr_and_dprx_caps - detect LTTPR and DPRX caps, init the LTTPR link training mode * @intel_dp: Intel DP struct * - * Read the LTTPR common capabilities, switch to non-transparent link training - * mode if any is detected and read the PHY capabilities for all detected - * LTTPRs. In case of an LTTPR detection error or if the number of + * Read the LTTPR common and DPRX capabilities and switch to non-transparent + * link training mode if any is detected and read the PHY capabilities for all + * detected LTTPRs. In case of an LTTPR detection error or if the number of * LTTPRs is more than is supported (8), fall back to the no-LTTPR, * transparent mode link training mode. * * Returns: - * >0 if LTTPRs were detected and the non-transparent LT mode was set + * >0 if LTTPRs were detected and the non-transparent LT mode was set. The + * DPRX capabilities are read out. * 0 if no LTTPRs or more than 8 LTTPRs were detected or in case of a - * detection failure and the transparent LT mode was set + * detection failure and the transparent LT mode was set. The DPRX + * capabilities are read out. + * <0 Reading out the DPRX capabilities failed. */ -int intel_dp_lttpr_init(struct intel_dp *intel_dp) +int intel_dp_init_lttpr_and_dprx_caps(struct intel_dp *intel_dp) { int lttpr_count; bool ret; int i; ret = intel_dp_read_lttpr_common_caps(intel_dp); + + /* The DPTX shall read the DRPX caps after LTTPR detection. */ + if (drm_dp_read_dpcd_caps(&intel_dp->aux, intel_dp->dpcd)) { + intel_dp_reset_lttpr_common_caps(intel_dp); + return -EIO; + } + if (!ret) return 0; + /* + * The 0xF0000-0xF02FF range is only valid if the DPCD revision is + * at least 1.4. + */ + if (intel_dp->dpcd[DP_DPCD_REV] < 0x14) { + intel_dp_reset_lttpr_common_caps(intel_dp); + return 0; + } + lttpr_count = drm_dp_lttpr_count(intel_dp->lttpr_common_caps); /* * Prevent setting LTTPR transparent mode explicitly if no LTTPRs are @@ -182,7 +205,7 @@ int intel_dp_lttpr_init(struct intel_dp *intel_dp) return lttpr_count; } -EXPORT_SYMBOL(intel_dp_lttpr_init); +EXPORT_SYMBOL(intel_dp_init_lttpr_and_dprx_caps); static u8 dp_voltage_max(u8 preemph) { @@ -817,7 +840,10 @@ void intel_dp_start_link_train(struct intel_dp *intel_dp, * TODO: Reiniting LTTPRs here won't be needed once proper connector * HW state readout is added. */ - int lttpr_count = intel_dp_lttpr_init(intel_dp); + int lttpr_count = intel_dp_init_lttpr_and_dprx_caps(intel_dp); + + if (lttpr_count < 0) + return; if (!intel_dp_link_train_all_phys(intel_dp, crtc_state, lttpr_count)) intel_dp_schedule_fallback_link_training(intel_dp, crtc_state); diff --git a/drivers/gpu/drm/i915/display/intel_dp_link_training.h b/drivers/gpu/drm/i915/display/intel_dp_link_training.h index 6a1f76bd8c75..9cb7c28027f0 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_link_training.h +++ b/drivers/gpu/drm/i915/display/intel_dp_link_training.h @@ -11,7 +11,7 @@ struct intel_crtc_state; struct intel_dp; -int intel_dp_lttpr_init(struct intel_dp *intel_dp); +int intel_dp_init_lttpr_and_dprx_caps(struct intel_dp *intel_dp); void intel_dp_get_adjust_train(struct intel_dp *intel_dp, const struct intel_crtc_state *crtc_state,