From mboxrd@z Thu Jan 1 00:00:00 1970 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=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 27604C433DB for ; Mon, 25 Jan 2021 17:36:49 +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 DDBC022B3F for ; Mon, 25 Jan 2021 17:36:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DDBC022B3F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6881588E14; Mon, 25 Jan 2021 17:36:43 +0000 (UTC) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) by gabe.freedesktop.org (Postfix) with ESMTPS id EF79989A74 for ; Mon, 25 Jan 2021 17:36:41 +0000 (UTC) IronPort-SDR: l5VgwLstOFJwd5w8H4IggxD/CTfT+XZZgrt85SN3D5EOJnjq0MEDSbQsikSOO4PreOpzMCujep ZPmBEhpCOCfw== X-IronPort-AV: E=McAfee;i="6000,8403,9875"; a="198548762" X-IronPort-AV: E=Sophos;i="5.79,374,1602572400"; d="scan'208";a="198548762" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 25 Jan 2021 09:36:41 -0800 IronPort-SDR: SS+t5iJRs09DMk6QYOyzzfYVPVmMxIXKqlKZ7nzHO6kZmW7Y3RpzamfrzdWD/tM1xxIZ4va1pL quJEHqucNfFg== X-IronPort-AV: E=Sophos;i="5.79,374,1602572400"; d="scan'208";a="368762541" 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 09:36:40 -0800 From: Imre Deak To: intel-gfx@lists.freedesktop.org Date: Mon, 25 Jan 2021 19:36:36 +0200 Message-Id: <20210125173636.1733812-2-imre.deak@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210125173636.1733812-1-imre.deak@intel.com> References: <20210125173636.1733812-1-imre.deak@intel.com> MIME-Version: 1.0 Subject: [Intel-gfx] [PATCH 2/2] drm/i915: Fix the MST PBN divider calculation 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: Ville Syrjala , stable@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Atm the driver will calculate a wrong MST timeslots/MTP (aka time unit) value for MST streams if the link parameters (link rate or lane count) are limited in a way independent of the sink capabilities (reported by DPCD). One example of such a limitation is when a MUX between the sink and source connects only a limited number of lanes to the display and connects the rest of the lanes to other peripherals (USB). Another issue is that atm MST core calculates the divider based on the backwards compatible DPCD (at address 0x0000) vs. the extended capability info (at address 0x2200). This can result in leaving some part of the MST BW unused (For instance in case of the WD19TB dock). Fix the above two issues by calculating the PBN divider value based on the rate and lane count link parameters that the driver uses for all other computation. Bugzilla: https://gitlab.freedesktop.org/drm/intel/-/issues/2977 Cc: Lyude Paul Cc: Ville Syrjala Cc: Signed-off-by: Imre Deak --- drivers/gpu/drm/i915/display/intel_dp_mst.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c index d6a1b961a0e8..b4621ed0127e 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c @@ -68,7 +68,9 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder, slots = drm_dp_atomic_find_vcpi_slots(state, &intel_dp->mst_mgr, connector->port, - crtc_state->pbn, 0); + crtc_state->pbn, + drm_dp_get_vc_payload_bw(crtc_state->port_clock, + crtc_state->lane_count)); if (slots == -EDEADLK) return slots; if (slots >= 0) -- 2.25.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx