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 E9A7DC19F2A for ; Thu, 11 Aug 2022 15:31:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234138AbiHKPbR (ORCPT ); Thu, 11 Aug 2022 11:31:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48306 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235948AbiHKPar (ORCPT ); Thu, 11 Aug 2022 11:30:47 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 09A9D99266; Thu, 11 Aug 2022 08:30:04 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 39CA561602; Thu, 11 Aug 2022 15:30:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B7F4DC433C1; Thu, 11 Aug 2022 15:30:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660231803; bh=TDZZwxVwyngwk48geYfv2U9/dcuIf5XnwjxGs8v7c1k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SCfooZLDxBa2N22n61MMaj1VZ5mIwYgARVhCuX9ZGvriORgD5Q/OZmo2QagOEv6P1 rmLG696cRhmOPKvk75FwRhlVtdpNCLgJRhER+JPMhRS73mzoNnGawVbLxqtJt3ME1Z 0Yp/8PdIeRfoY5yIRNucnhmI6h+TQL9McG/iQEkWy3hUi1QQA1KxbJ2zLl+mqhlX/z /edIEhIHuy87DJZHnVrpVIFn4qnNC7iQ6Zmmk2MiPtFYMWiuCJUaqFdoRA4h4a/42S OmONSQObn6jR2PxPfka3Y9FnV3MN2o2aqZl5weYyTsAGRq++V4IkJ2BJMfYj7ZabLT y0Z6UHRAeyccw== 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 5.19 012/105] drm/amd/display: Detect dpcd_rev when hotplug mst monitor Date: Thu, 11 Aug 2022 11:26:56 -0400 Message-Id: <20220811152851.1520029-12-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220811152851.1520029-1-sashal@kernel.org> References: <20220811152851.1520029-1-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: linux-kernel@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 2b9b095e5f03..1c02d873950d 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 @@ -361,12 +361,48 @@ 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