From patchwork Mon Jan 25 17:36:35 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Imre Deak X-Patchwork-Id: 370551 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, URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable 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 A735AC433E6 for ; Mon, 25 Jan 2021 17:43:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7DD0D22583 for ; Mon, 25 Jan 2021 17:43:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731228AbhAYRnj (ORCPT ); Mon, 25 Jan 2021 12:43:39 -0500 Received: from mga18.intel.com ([134.134.136.126]:23215 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731158AbhAYRh2 (ORCPT ); Mon, 25 Jan 2021 12:37:28 -0500 IronPort-SDR: lstio9Gt/6X6fIhKJWolCJRthbPgtmNgjFPD/Q7uZvhiRFyk7Ar4UUmYJwrF2BLl9R9MhPHSU6 Nsq8/BseUaog== X-IronPort-AV: E=McAfee;i="6000,8403,9875"; a="167443702" X-IronPort-AV: E=Sophos;i="5.79,374,1602572400"; d="scan'208";a="167443702" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Jan 2021 09:36:40 -0800 IronPort-SDR: vgcu1GNmi57TdNrpab78XpsZHoQXiP78L00DoQXG1C45CXV+L2z6cbKQAiOjkujaGF5IKLZDP+ X88HhnAZcleg== X-IronPort-AV: E=Sophos;i="5.79,374,1602572400"; d="scan'208";a="368762489" Received: from ideak-desk.fi.intel.com ([10.237.68.141]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Jan 2021 09:36:38 -0800 From: Imre Deak To: intel-gfx@lists.freedesktop.org Cc: Lyude Paul , Ville Syrjala , stable@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH 1/2] drm/dp/mst: Export drm_dp_get_vc_payload_bw() Date: Mon, 25 Jan 2021 19:36:35 +0200 Message-Id: <20210125173636.1733812-1-imre.deak@intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This function will be needed by the next patch where the driver calculates the BW based on driver specific parameters, so export it. At the same time sanitize the function params, passing the more natural link rate instead of the encoding of the same rate. Cc: Lyude Paul Cc: Ville Syrjala Cc: Cc: dri-devel@lists.freedesktop.org Signed-off-by: Imre Deak Reviewed-by: Lyude Paul --- drivers/gpu/drm/drm_dp_mst_topology.c | 24 ++++++++++++++++++------ include/drm/drm_dp_mst_helper.h | 1 + 2 files changed, 19 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 475939138b21..dc96cbf78cc6 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -3629,14 +3629,26 @@ static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, return 0; } -static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count) +/** + * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link + * @rate: link rate in 10kbits/s units + * @lane_count: lane count + * + * Calculate the toal bandwidth of a MultiStream Transport link. The returned + * value is in units of PBNs/(timeslots/1 MTP). This value can be used to + * convert the number of PBNs required for a given stream to the number of + * timeslots this stream requires in each MTP. + */ +int drm_dp_get_vc_payload_bw(int link_rate, int link_lane_count) { - if (dp_link_bw == 0 || dp_link_count == 0) - DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n", - dp_link_bw, dp_link_count); + if (link_rate == 0 || link_lane_count == 0) + DRM_DEBUG_KMS("invalid link rate/lane count: (%d / %d)\n", + link_rate, link_lane_count); - return dp_link_bw * dp_link_count / 2; + /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ + return link_rate * link_lane_count / 54000; } +EXPORT_SYMBOL(drm_dp_get_vc_payload_bw); /** * drm_dp_read_mst_cap() - check whether or not a sink supports MST @@ -3692,7 +3704,7 @@ int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool ms goto out_unlock; } - mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1], + mgr->pbn_div = drm_dp_get_vc_payload_bw(drm_dp_bw_code_to_link_rate(mgr->dpcd[1]), mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK); if (mgr->pbn_div == 0) { ret = -EINVAL; diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h index f5e92fe9151c..bd1c39907b92 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -783,6 +783,7 @@ drm_dp_mst_detect_port(struct drm_connector *connector, struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port); +int drm_dp_get_vc_payload_bw(int link_rate, int link_lane_count); int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc);