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=-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=unavailable 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 10043C43331 for ; Mon, 11 Nov 2019 18:59:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD54A204EC for ; Mon, 11 Nov 2019 18:59:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573498763; bh=S6M+qFPNNxKZi8+ayzw7dZiXwBdZinIsmA838tIe9u8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=tk1IWKjtkQ5TUTZescuK/RWjm/MSQkSVi1cXmvV07pTyrl5iTuCpCVTuUbMD2/nVS Yj/MyxXAcMOgN6V88tOPSBoMjRnDqdeQaVtC8gSIdy+ViKvjDA/9vw5zl9uV7QiZR+ 0HtTEKeQLnAUMN96CBgASY7zfcwuSrvcaU7VfW8c= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730075AbfKKS4q (ORCPT ); Mon, 11 Nov 2019 13:56:46 -0500 Received: from mail.kernel.org ([198.145.29.99]:55392 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730745AbfKKS4q (ORCPT ); Mon, 11 Nov 2019 13:56:46 -0500 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 CFF3621783; Mon, 11 Nov 2019 18:56:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573498605; bh=S6M+qFPNNxKZi8+ayzw7dZiXwBdZinIsmA838tIe9u8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BSAQLB6cM+M/uM7l5KH76J+crykupQsIc3MPWc+Bu3X9uX58W3kJQMTxoAfONiK8x P18SLf2e1rGeIR5bq3tr/JzFYusZlwpSMPxO8VzlygZB4zByo/CYwhdBHYg4yPZFzK JpmAv7iiqHpUfP+zaHFClkb1IKtB2uVTx7QeE3BQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Michael Strauss , Tony Cheng , Leo Li , Alex Deucher , Sasha Levin Subject: [PATCH 5.3 169/193] drm/amd/display: Passive DP->HDMI dongle detection fix Date: Mon, 11 Nov 2019 19:29:11 +0100 Message-Id: <20191111181513.595771505@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191111181459.850623879@linuxfoundation.org> References: <20191111181459.850623879@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Michael Strauss [ Upstream commit bc2fde42e2418808dbfc04de1a6da91d7d31cf1a ] [WHY] i2c_read is called to differentiate passive DP->HDMI and DP->DVI-D dongles The call is expected to fail in DVI-D case but pass in HDMI case Some HDMI dongles have a chance to fail as well, causing misdetection as DVI-D [HOW] Retry i2c_read to ensure failed result is valid Signed-off-by: Michael Strauss Reviewed-by: Tony Cheng Acked-by: Leo Li Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- .../gpu/drm/amd/display/dc/core/dc_link_ddc.c | 24 ++++++++++++++----- 1 file changed, 18 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c index e6da8506128bd..623c1ab4d3db2 100644 --- a/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c +++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_ddc.c @@ -374,6 +374,7 @@ void dal_ddc_service_i2c_query_dp_dual_mode_adaptor( enum display_dongle_type *dongle = &sink_cap->dongle_type; uint8_t type2_dongle_buf[DP_ADAPTOR_TYPE2_SIZE]; bool is_type2_dongle = false; + int retry_count = 2; struct dp_hdmi_dongle_signature_data *dongle_signature; /* Assume we have no valid DP passive dongle connected */ @@ -386,13 +387,24 @@ void dal_ddc_service_i2c_query_dp_dual_mode_adaptor( DP_HDMI_DONGLE_ADDRESS, type2_dongle_buf, sizeof(type2_dongle_buf))) { - *dongle = DISPLAY_DONGLE_DP_DVI_DONGLE; - sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_DVI_MAX_TMDS_CLK; + /* Passive HDMI dongles can sometimes fail here without retrying*/ + while (retry_count > 0) { + if (i2c_read(ddc, + DP_HDMI_DONGLE_ADDRESS, + type2_dongle_buf, + sizeof(type2_dongle_buf))) + break; + retry_count--; + } + if (retry_count == 0) { + *dongle = DISPLAY_DONGLE_DP_DVI_DONGLE; + sink_cap->max_hdmi_pixel_clock = DP_ADAPTOR_DVI_MAX_TMDS_CLK; - CONN_DATA_DETECT(ddc->link, type2_dongle_buf, sizeof(type2_dongle_buf), - "DP-DVI passive dongle %dMhz: ", - DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000); - return; + CONN_DATA_DETECT(ddc->link, type2_dongle_buf, sizeof(type2_dongle_buf), + "DP-DVI passive dongle %dMhz: ", + DP_ADAPTOR_DVI_MAX_TMDS_CLK / 1000); + return; + } } /* Check if Type 2 dongle.*/ -- 2.20.1