From patchwork Sat Apr 11 12:08:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 228085 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,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 33653C2BB85 for ; Sat, 11 Apr 2020 12:15:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 098FF21D7F for ; Sat, 11 Apr 2020 12:15:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586607308; bh=64g/FuVY4FkADB9UpvuwvHmWfRLDc5mR7iw725sbOe8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RQxaL/Pk0v7JTtXz4FoTgKC4S1nBsxHbJaB1Iw/1zfyjLLCnr6IJ6s0jN3ROjq4zM vOHK1V3LHRxuhf5AEPQIj3UbGmNdktqvCX9U+PyK9QNi6WQL7jE4uCEiXq9X+anPGZ j1uQXNka6Fh4QyrimuFpqJR1XSBV0YY52MnDtf+A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727034AbgDKMPG (ORCPT ); Sat, 11 Apr 2020 08:15:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:48856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726934AbgDKMPF (ORCPT ); Sat, 11 Apr 2020 08:15:05 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 46BA620692; Sat, 11 Apr 2020 12:15:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586607305; bh=64g/FuVY4FkADB9UpvuwvHmWfRLDc5mR7iw725sbOe8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xEhBmJgBrboQWKRA8HHhCvzQ/m1SwjX47inhuE+6UbDsP9e9pQ/s4ys5NnZB5Eezn 7ZgRBM5JZYEl1JeNCIlgWolvMcIHLChtHFcAD9uoBSbjIrQX5EOpWhzAjBr/R26GC/ ofgQVyKDeOsGO+MW7xAsqyZaXWdYSu6Xd/uCwIig= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mario Kleiner , Alex Deucher , Sasha Levin Subject: [PATCH 4.19 06/54] drm/amd/display: Add link_rate quirk for Apple 15" MBP 2017 Date: Sat, 11 Apr 2020 14:08:48 +0200 Message-Id: <20200411115508.931334215@linuxfoundation.org> X-Mailer: git-send-email 2.26.0 In-Reply-To: <20200411115508.284500414@linuxfoundation.org> References: <20200411115508.284500414@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Mario Kleiner [ Upstream commit dec9de2ada523b344eb2428abfedf9d6cd0a0029 ] This fixes a problem found on the MacBookPro 2017 Retina panel: The panel reports 10 bpc color depth in its EDID, and the firmware chooses link settings at boot which support enough bandwidth for 10 bpc (324000 kbit/sec aka LINK_RATE_RBR2 aka 0xc), but the DP_MAX_LINK_RATE dpcd register only reports 2.7 Gbps (multiplier value 0xa) as possible, in direct contradiction of what the firmware successfully set up. This restricts the panel to 8 bpc, not providing the full color depth of the panel on Linux <= 5.5. Additionally, commit '4a8ca46bae8a ("drm/amd/display: Default max bpc to 16 for eDP")' introduced into Linux 5.6-rc1 will unclamp panel depth to its full 10 bpc, thereby requiring a eDP bandwidth for all modes that exceeds the bandwidth available and causes all modes to fail validation -> No modes for the laptop panel -> failure to set any mode -> Panel goes dark. This patch adds a quirk specific to the MBP 2017 15" Retina panel to override reported max link rate to the correct maximum of 0xc = LINK_RATE_RBR2 to fix the darkness and reduced display precision. Please apply for Linux 5.6+ to avoid regressing Apple MBP panel support. Signed-off-by: Mario Kleiner Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c index 122249da03ab7..a4928854a3de5 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c @@ -2440,6 +2440,17 @@ static bool retrieve_link_cap(struct dc_link *link) sink_id.ieee_device_id, sizeof(sink_id.ieee_device_id)); + /* Quirk Apple MBP 2017 15" Retina panel: Wrong DP_MAX_LINK_RATE */ + { + uint8_t str_mbp_2017[] = { 101, 68, 21, 101, 98, 97 }; + + if ((link->dpcd_caps.sink_dev_id == 0x0010fa) && + !memcmp(link->dpcd_caps.sink_dev_id_str, str_mbp_2017, + sizeof(str_mbp_2017))) { + link->reported_link_cap.link_rate = 0x0c; + } + } + core_link_read_dpcd( link, DP_SINK_HW_REVISION_START,