From patchwork Mon Feb 8 15:01:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 12075851 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=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 668D4C433E0 for ; Mon, 8 Feb 2021 15:15:48 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 1405364EFA for ; Mon, 8 Feb 2021 15:15:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1405364EFA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 637D56E901; Mon, 8 Feb 2021 15:15:47 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9AA1F6E901 for ; Mon, 8 Feb 2021 15:15:46 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id B2FA864F20; Mon, 8 Feb 2021 15:15:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1612797346; bh=2ktO6u/bOQJqlEHKKcuoK+7PPWci1WCWMSoeppvCyiI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NmeHZ0T+Z0eosxr9d7jdPqLOX/J7lIuBfAGL4Ud3q/BwTmXnOQipr22I+RMvEzjU1 U+XQft5Rz7Ip4RDVgMDN/hUAUTINq6Og3AnzBYNJmvUIOe9kCJTcxpC3i/XWpC1QL/ Y7JUuUwJQk1Nb7Qr6QwdFNmHFtXZaPmCuQYSbP6M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Subject: [PATCH 5.10 078/120] drm/dp/mst: Export drm_dp_get_vc_payload_bw() Date: Mon, 8 Feb 2021 16:01:05 +0100 Message-Id: <20210208145821.517331268@linuxfoundation.org> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20210208145818.395353822@linuxfoundation.org> References: <20210208145818.395353822@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jani Nikula , Greg Kroah-Hartman , dri-devel@lists.freedesktop.org, stable@vger.kernel.org, Ville Syrjala Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" From: Imre Deak commit 83404d581471775f37f85e5261ec0d09407d8bed upstream. 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. v2: - Fix function documentation. (Lyude) Cc: Lyude Paul Cc: Ville Syrjala Cc: Cc: dri-devel@lists.freedesktop.org Signed-off-by: Imre Deak Reviewed-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20210125173636.1733812-1-imre.deak@intel.com (cherry picked from commit a321fc2b4e60fc1b39517d26c8104351636a6062) Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_dp_mst_topology.c | 24 ++++++++++++++++++------ include/drm/drm_dp_mst_helper.h | 1 + 2 files changed, 19 insertions(+), 6 deletions(-) --- 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(stru 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 + * @link_rate: link rate in 10kbits/s units + * @link_lane_count: lane count + * + * Calculate the total 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(stru 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; --- 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_connec 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);