From patchwork Sat Jan 27 06:36:26 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Murthy, Arun R" X-Patchwork-Id: 13533979 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 3F07EC46CD2 for ; Sat, 27 Jan 2024 06:46:46 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AE06510E55D; Sat, 27 Jan 2024 06:46:41 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) by gabe.freedesktop.org (Postfix) with ESMTPS id 8DEF410E55C; Sat, 27 Jan 2024 06:46:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1706338001; x=1737874001; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=aYDRSgaKsu91Ksbkz9dTbqiV0DGXxzfLUrPJ+gPF3Sk=; b=UvNiTh8lgSYosc+0deP13JY2h6oHEHL0wFhUsLXf85eXSHXKD+dbc83A 8o55kNLGewRYnS9HgdXy9VjLQLl1goQ6yrOnUp/nn+wjRiXSy01aSVpGD sLCpJEaePmVC3JWJ637yaVIqK8/8D18mVFHDwmLvR0Vecg3oQ4/Bdi+mT U0DvenX3AhGNcL+cCobixHwJJNXc4Ba5HKpZbt3faCXhnuE8cZIbwJQRa RIb1ClJJivU3riNKEOPam5hGNtYuq3rJGe1P3quyi+/8wHb+daRgn8tzt 6gp5QTxFR86geIQ0+U/KW7D1R0ZnLMZUqCwsMVhot2ExXjgD06E5j6rjX w==; X-IronPort-AV: E=McAfee;i="6600,9927,10964"; a="24120170" X-IronPort-AV: E=Sophos;i="6.05,220,1701158400"; d="scan'208";a="24120170" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2024 22:46:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,220,1701158400"; d="scan'208";a="35636988" Received: from srr4-3-linux-106-armuthy.iind.intel.com ([10.190.238.56]) by orviesa001.jf.intel.com with ESMTP; 26 Jan 2024 22:46:39 -0800 From: Arun R Murthy To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Subject: [PATCH 1/2] drm/display/dp: Check for MSTM_CAP before MSTM_CTRL write Date: Sat, 27 Jan 2024 12:06:26 +0530 Message-Id: <20240127063627.1369883-1-arun.r.murthy@intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jani.nikula@intel.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" With DP2.1, multistream packetization and the underneth MST protocol will be required for SST. So check for MSTM_CAP to see if MST is really required and skip the MSTM_CTRL write so that we ensure that only the underneth protocol and the multistream packetization will be enabled and sink will not be confused by a corresponding dpcd write. Signed-off-by: Arun R Murthy --- drivers/gpu/drm/display/drm_dp_mst_topology.c | 26 +++++++++++-------- 1 file changed, 15 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c index 8ca01a6bf645..22d81732a978 100644 --- a/drivers/gpu/drm/display/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c @@ -3666,10 +3666,11 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms mgr->mst_primary = mstb; drm_dp_mst_topology_get_mstb(mgr->mst_primary); - ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, - DP_MST_EN | - DP_UP_REQ_EN | - DP_UPSTREAM_IS_SRC); + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd)) + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, + DP_MST_EN | + DP_UP_REQ_EN | + DP_UPSTREAM_IS_SRC); if (ret < 0) goto out_unlock; @@ -3684,7 +3685,8 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms mstb = mgr->mst_primary; mgr->mst_primary = NULL; /* this can fail if the device is gone */ - drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd)) + drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); ret = 0; mgr->payload_id_table_cleared = false; @@ -3724,8 +3726,9 @@ drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb) void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) { mutex_lock(&mgr->lock); - drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, - DP_MST_EN | DP_UPSTREAM_IS_SRC); + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd)) + drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, + DP_MST_EN | DP_UPSTREAM_IS_SRC); mutex_unlock(&mgr->lock); flush_work(&mgr->up_req_work); flush_work(&mgr->work); @@ -3773,10 +3776,11 @@ int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr, goto out_fail; } - ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, - DP_MST_EN | - DP_UP_REQ_EN | - DP_UPSTREAM_IS_SRC); + if (drm_dp_read_mst_cap(mgr->aux, mgr->dpcd)) + ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, + DP_MST_EN | + DP_UP_REQ_EN | + DP_UPSTREAM_IS_SRC); if (ret < 0) { drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); goto out_fail; From patchwork Sat Jan 27 06:36:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Murthy, Arun R" X-Patchwork-Id: 13533980 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B8020C47DDB for ; Sat, 27 Jan 2024 06:46:50 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 72D2210E564; Sat, 27 Jan 2024 06:46:47 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) by gabe.freedesktop.org (Postfix) with ESMTPS id E31AB10E562; Sat, 27 Jan 2024 06:46:44 +0000 (UTC) DKIM-Signature: v=1; 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26 Jan 2024 22:46:44 -0800 From: Arun R Murthy To: dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org Subject: [PATCH 2/2] drm/i915/display/dp: 128/132b DP-capable with SST Date: Sat, 27 Jan 2024 12:06:27 +0530 Message-Id: <20240127063627.1369883-2-arun.r.murthy@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240127063627.1369883-1-arun.r.murthy@intel.com> References: <20240127063627.1369883-1-arun.r.murthy@intel.com> MIME-Version: 1.0 X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jani.nikula@intel.com Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" With a value of '0' read from MSTM_CAP register MST to be enabled. DP2.1 SCR updates the spec for 128/132b DP capable supporting only one stream and not supporting single stream sideband MSG. The underlying protocol will be MST to enable use of MTP. Signed-off-by: Arun R Murthy --- drivers/gpu/drm/i915/display/intel_dp.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 9ff0cbd9c0df..05722f10cdd7 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -4037,9 +4037,15 @@ intel_dp_configure_mst(struct intel_dp *intel_dp) if (!intel_dp_mst_source_support(intel_dp)) return; - - intel_dp->is_mst = sink_can_mst && - i915->display.params.enable_dp_mst; + /* + * Even if dpcd reg MSTM_CAP is 0, if the sink supports UHBR rates then + * DP2.1 can be enabled with underlying protocol using MST for MTP + * TODO: Need to accommodate MSTM_CAP bit[0]=0, bit[1]=1 condition, i.e + * one stream with single stream sideband msg. + */ + intel_dp->is_mst = (sink_can_mst || (intel_dp->dpcd[DP_MAIN_LINK_CHANNEL_CODING] & + DP_CAP_ANSI_128B132B)) && + i915->display.params.enable_dp_mst; drm_dp_mst_topology_mgr_set_mst(&intel_dp->mst_mgr, intel_dp->is_mst);