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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C229C25B0D for ; Thu, 11 Aug 2022 15:52:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235399AbiHKPwu (ORCPT ); Thu, 11 Aug 2022 11:52:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236835AbiHKPvs (ORCPT ); Thu, 11 Aug 2022 11:51:48 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 868DD98CBF; Thu, 11 Aug 2022 08:44:01 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id F2A16CE225D; Thu, 11 Aug 2022 15:43:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF677C433C1; Thu, 11 Aug 2022 15:43:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660232638; bh=3rN/T8Jde922Nv2ildGBzsoOl8hKjx9VEx2KhnzC9Ik=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a5oXq7iyJZtt1dv/Okh8oMUbuSBIZa7CLjt6UOd3oPQIFDZawk7ElocQnvfz7oHvA BW9hp7xRCVkXA+BJc55FE1WgbJJGz3WHq5WnrpkiUopzt8K9VIkHdRdEMBBKnuWDlS tPrkUnxVuWZZe6zKzWbWY70PpT9UwiLpAa0scF9N6YQF6xANOdmFASk8xd1TRlwIH+ b+bVfvJqpWyTCD6hw8C3BQ0Jq0EeHYUDKFYh9Mr79/ZuMUG+IAyXShCHDcjtn+/sGi BCZj+9w1wzRhkzegY4bEdMaK4Byw2G9nS17O0WuAR2aCl+o4f81nCv12YDqyl5YGOO BC4eMoHdB6jJQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wayne Lin , Hersen Wu , Hamza Mahfooz , Daniel Wheeler , Alex Deucher , Sasha Levin , harry.wentland@amd.com, sunpeng.li@amd.com, Rodrigo.Siqueira@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@linux.ie, daniel@ffwll.ch, Jerry.Zuo@amd.com, Roman.Li@amd.com, nicholas.kazlauskas@amd.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.18 12/93] drm/amd/display: Detect dpcd_rev when hotplug mst monitor Date: Thu, 11 Aug 2022 11:41:06 -0400 Message-Id: <20220811154237.1531313-12-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220811154237.1531313-1-sashal@kernel.org> References: <20220811154237.1531313-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wayne Lin [ Upstream commit 453b0016a054df0f442fda8a145b97a33816cab9 ] [Why] Once mst topology is constructed, later on new connected monitors are reported to source by CSN message. Within CSN, there is no carried info of DPCD_REV comparing to LINK_ADDRESS reply. As the result, we might leave some ports connected to DP but without DPCD revision number which will affect us determining the capability of the DP Rx. [How] Send out remote DPCD read when the port's dpcd_rev is 0x0 in detect_ctx(). Firstly, read out the value from DPCD 0x2200. If the return value is 0x0, it's likely the DP1.2 DP Rx then we reques revision from DPCD 0x0 again. Reviewed-by: Hersen Wu Acked-by: Hamza Mahfooz Signed-off-by: Wayne Lin Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- .../display/amdgpu_dm/amdgpu_dm_mst_types.c | 38 ++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c index d864cae1af67..bcbb6f6f8c82 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c @@ -363,12 +363,48 @@ dm_dp_mst_detect(struct drm_connector *connector, { struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector); struct amdgpu_dm_connector *master = aconnector->mst_port; + struct drm_dp_mst_port *port = aconnector->port; + int connection_status; if (drm_connector_is_unregistered(connector)) return connector_status_disconnected; - return drm_dp_mst_detect_port(connector, ctx, &master->mst_mgr, + connection_status = drm_dp_mst_detect_port(connector, ctx, &master->mst_mgr, aconnector->port); + + if (port->pdt != DP_PEER_DEVICE_NONE && !port->dpcd_rev) { + uint8_t dpcd_rev; + int ret; + + ret = drm_dp_dpcd_readb(&port->aux, DP_DP13_DPCD_REV, &dpcd_rev); + + if (ret == 1) { + port->dpcd_rev = dpcd_rev; + + /* Could be DP1.2 DP Rx case*/ + if (!dpcd_rev) { + ret = drm_dp_dpcd_readb(&port->aux, DP_DPCD_REV, &dpcd_rev); + + if (ret == 1) + port->dpcd_rev = dpcd_rev; + } + + if (!dpcd_rev) + DRM_DEBUG_KMS("Can't decide DPCD revision number!"); + } + + /* + * Could be legacy sink, logical port etc on DP1.2. + * Will get Nack under these cases when issue remote + * DPCD read. + */ + if (ret != 1) + DRM_DEBUG_KMS("Can't access DPCD"); + } else if (port->pdt == DP_PEER_DEVICE_NONE) { + port->dpcd_rev = 0; + } + + return connection_status; } static int dm_dp_mst_atomic_check(struct drm_connector *connector, -- 2.35.1