From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2624D1CDFC1; Sun, 24 Nov 2024 13:41:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732455695; cv=none; b=OfpOyvnfdCXuYMEDRDhLYi5iMOGusTEv4rs/sCD4e02G+yIfDarY7+/MRK0kHzr8C5Zv/HDLd857zs31UjSh+GmqDMgE3y+RYpgh+/J9ASc8OSkIkhCm1omnTiHIcCSTOZaPsTu3bUHZ4nHntbVnucj88FygKhvu8BD98RlC5As= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732455695; c=relaxed/simple; bh=CpRPvOOUGihhsBREB3zmzzH4lVmAi3W3BoQar+F2gG4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QJKiqs+TeXaD4cnESIPUXtfDmnGTT8LEGeiDUiSqJmoCfwc9pNlE0j1oKarI9IWIy1B3yhOACl2u5skqZV2KREXzevUWaUuBxTU2qZCN8UweiMKr4eS4OMZOQcZGiHw6ulIIwVLMfH1ZUL8ZNZPoF/X62oGzoPwhPBCdP7Ou/zQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=X6lvzjYl; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="X6lvzjYl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C328FC4CED1; Sun, 24 Nov 2024 13:41:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1732455695; bh=CpRPvOOUGihhsBREB3zmzzH4lVmAi3W3BoQar+F2gG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=X6lvzjYlwo9isUwQ349FguT1+XsKM4+L+JoigE4ZKCslvs5YfFeOCIzoPD22FTScV LcRLceqJ3pnaQE/nCmgcMaEemXF2+QuUyBqX9zZVY1taSa7GafAuDTGUKBEw+v0Qxm R7KkPQtZ6xGDrStZGSlvk2uiBW3o1y+i8zNMwsOX3fTBPsWZEPtd77ezlZg0CVNWIz 9QpZi8sjRrw5Cr+5k11TlAwc9A20w0Cwu4ARf3sgyYigtUfPFJfk3+FsBs1g1x1Yl/ xa5/FADe7V7yZBUFr+BZzThN8HxzfUZI6WQnjVQUn7qRaMfKXvY5nwlEFuo7J90Bdg z9bJVLRAfWViA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Michael Strauss , Wenjing Liu , Ovidiu Bunea , Aurabindo Pillai , 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@gmail.com, simona@ffwll.ch, alex.hung@amd.com, george.shen@amd.com, daniel.sa@amd.com, Ausef.Yousof@amd.com, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 6.11 15/87] drm/amd/display: Block UHBR Based On USB-C PD Cable ID Date: Sun, 24 Nov 2024 08:37:53 -0500 Message-ID: <20241124134102.3344326-15-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241124134102.3344326-1-sashal@kernel.org> References: <20241124134102.3344326-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.11.10 Content-Transfer-Encoding: 8bit From: Michael Strauss [ Upstream commit 4f01a68751194d05280d659a65758c09e4af04d6 ] [WHY] Currently the absence of UHBR cable ID caps from USB-C PD does not block UHBR rates. In situations where DPCD reports valid UHBR capability but USB-C PD does not, such as using a USB-C to DP1.4 dongle connected to a native DP2.1 cable, link loss and lightup failures can be seen as a result. Additionally, in edge cases where a platform supports cable ID but DMUB doesn't correctly return cable ID caps, driver currently also allows UHBR. [HOW] Block UHBR rates over DP alt mode if cable id indicates no UHBR support. Additionally, block UHBR rates if a cable ID supported platform receives no reply from a DMUB cable id query. Reviewed-by: Wenjing Liu Reviewed-by: Ovidiu Bunea Signed-off-by: Michael Strauss Signed-off-by: Aurabindo Pillai Tested-by: Daniel Wheeler Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- .../dc/link/protocols/link_dp_capability.c | 22 ++++++++++++++----- 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c index 60015e94c4aa8..ae6d7e3d117e2 100644 --- a/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c +++ b/drivers/gpu/drm/amd/display/dc/link/protocols/link_dp_capability.c @@ -1402,7 +1402,8 @@ static bool get_usbc_cable_id(struct dc_link *link, union dp_cable_id *cable_id) if (!link->ctx->dmub_srv || link->ep_type != DISPLAY_ENDPOINT_PHY || - link->link_enc->features.flags.bits.DP_IS_USB_C == 0) + link->link_enc->features.flags.bits.DP_IS_USB_C == 0 || + link->link_enc->features.flags.bits.IS_DP2_CAPABLE == 0) return false; memset(&cmd, 0, sizeof(cmd)); @@ -1415,7 +1416,9 @@ static bool get_usbc_cable_id(struct dc_link *link, union dp_cable_id *cable_id) cable_id->raw = cmd.cable_id.data.output_raw; DC_LOG_DC("usbc_cable_id = %d.\n", cable_id->raw); } - return cmd.cable_id.header.ret_status == 1; + + ASSERT(cmd.cable_id.header.ret_status); + return true; } static void retrieve_cable_id(struct dc_link *link) @@ -2087,6 +2090,8 @@ struct dc_link_settings dp_get_max_link_cap(struct dc_link *link) /* get max link encoder capability */ if (link_enc) link_enc->funcs->get_max_link_cap(link_enc, &max_link_cap); + else + return max_link_cap; /* Lower link settings based on sink's link cap */ if (link->reported_link_cap.lane_count < max_link_cap.lane_count) @@ -2120,10 +2125,15 @@ struct dc_link_settings dp_get_max_link_cap(struct dc_link *link) */ cable_max_link_rate = get_cable_max_link_rate(link); - if (!link->dc->debug.ignore_cable_id && - cable_max_link_rate != LINK_RATE_UNKNOWN) { - if (cable_max_link_rate < max_link_cap.link_rate) - max_link_cap.link_rate = cable_max_link_rate; + if (!link->dc->debug.ignore_cable_id) { + if (cable_max_link_rate != LINK_RATE_UNKNOWN) + // cable max link rate known + max_link_cap.link_rate = MIN(max_link_cap.link_rate, cable_max_link_rate); + else if (link_enc->funcs->is_in_alt_mode && link_enc->funcs->is_in_alt_mode(link_enc)) + // cable max link rate ambiguous, DP alt mode, limit to HBR3 + max_link_cap.link_rate = MIN(max_link_cap.link_rate, LINK_RATE_HIGH3); + //else {} + // cable max link rate ambiguous, DP, do nothing if (!link->dpcd_caps.cable_id.bits.UHBR13_5_CAPABILITY && link->dpcd_caps.cable_id.bits.CABLE_TYPE >= 2) -- 2.43.0